2010 volumne 31卷 Issue 03
ZHOU Cairong; SHI Xiaohua; Ge Chengbo; etc

Abstract:
From the perspective of energy saving, green and environmental protection, the solid superacid (SO42-/TiO2) was used as the catalyst to prepare chloroacetic acid high-carbon fatty alcohol ester, using the orthogonal test method, taking the esterification rate as the investigation index, the influence of five factors on the reaction was investigated, and the order of the influence was as follows: reaction time> amount of water agent> material ratio>catalyst dosage> reaction temperature, and the better reaction conditions were obtained: reaction temperature 5 °C, reaction time 110.5 h. The material ratio was 5:1.1 (n solution: n acid), the catalyst dosage was 157%, the amount of aqueous agent was 4 mL, and the esterification rate reached 30.87%.The activity and reproducibility of the solid superacid catalyst were investigated, and the results showed that the activity and reproducibility of the synthesis of chloroacetic acid high-carbon fatty alcohol ester catalyzed by this solid superacid were good.

LI Huiping; CHENG Kang; Hao Lingfang; etc

Abstract:
At present, the common perfluorosulfonate membrane has high proton conductivity, but due to its proton conduction mechanism, it shows functionalization at lower temperature and high relative humidity, which limits its practical application. A proton conductor 4-(1-methoxybenzyl)-4-hydroxymethyl-4,1,2-triazole was obtained by chlorination, azide substitution and Click Chemistry cycloaddition reaction using 3-methoxybenzyl alcohol as raw material, which could be used to prepare a novel polymer electrolyte membrane. The process is environmentally friendly and the reaction conditions are mild. The structure of the synthetic product was identified by FTIR and NMR, and the feasibility of the synthetic route was confirmed, and the total yield of the reaction was 38.4%.

Wang Liucheng; WANG Wentian; ZHAO Jianhong; etc

Abstract:
C1-C2-C10 asymmetric biquaternary ammonium surfactant was synthesized from 2,12-dibromoethane, N,N-dimethyldecyltertiary amine and N,N-dimethyldodecyl tertiary amine as raw materials, and the effects of molar ratio and temperature on the synthesis reaction were investigated, and the better process conditions of the synthetic product were obtained, under which the yield reached 90% and the content was higher than 86%.

Yang Libin; Wang Yanfei; Zeng to the east; etc

Abstract:
The crystal habit of iminodiacetonitrile crystals was investigated, the solubility and metastable zone data of iminodiacetonitrile in aqueous solution were determined, and the influence of cooling rate on the width of the metastable zone was investigated. The results showed that the solubility of iminodiacetonitrile in water increased with the increase of temperature, and the increase range was large at high temperature. The faster the cooling, the wider the metastable zone of the crystallization process, that is, the greater the supersaturation of the system.

Shen Guopeng; LIANG Chunli; GE Qingping; etc

Abstract:
In order to improve the efficacy of 5-fluorouracil (5-Fu) preparation and reduce the toxic side effects, 5-fluorouracil magnetic solid lipid nanoparticles (5-Fu-MSLN) were prepared by re-emulsification-solvent volatilization method with glyceryl monostearate as the carrier, hydrogenated soy lecithin and poloxamer as emulsifiers, and magnetic nano-ferric oxide as magnets. Observed by transmission electron microscopy, the appearance of magnetic solid lipid nanoparticles was round, and the particle size distribution was uniform. Observed under an inverted microscope, magnetic solid lipid nanoparticles have good in vitro magnetic responsiveness, and experimental results show that 5-FU-MSLN is a promising targeted preparation for intravenous administration.

WANG Dan; Dong Qiwu; Liu Minshan

Abstract:
Through the analysis of the fluid flow and heat transfer characteristics of the shell of the baffle plate shell and tube heat exchanger, a comprehensive simulation method of one module is proposed. In this method, the shell range of the baffle plate shell and tube heat exchanger is divided into inlet section, cycle section and outlet section, and the simulation calculation is carried out separately, and then the temperature difference and pressure drop of the whole shell range are synthesized by synthesizing the simulation results of each part. Through the heat transfer performance experiment and numerical simulation results of shell and tube heat exchanger, the two are in good agreement, which proves the correctness of the numerical simulation method. The modular synthesis method can reduce the number of meshes in the calculation model, improve the calculation speed, and has high accuracy, which can be used for the simulation calculation of larger shell and tube heat exchangers, which makes up for the shortcomings of traditional simulation methods.

JIN Zunlong; Dong Qiwu; Liu Minshan

Abstract:
Using the inherent linear properties between the inlet and outlet temperatures of the heat exchange network, the concept of temperature transfer coefficient is proposed on the basis of theoretical analysis, and the influence of temperature fluctuation of heat exchange network is quantitatively analyzed, so as to determine the transfer property of temperature fluctuation in the system. Calculate the effects of temperature fluctuations in the system to obtain data and information that need to be improved in the heat exchange network. The example results calculated by the temperature transfer coefficient method of heat exchange network are of positive significance for guiding actual production. Through the temperature transfer coefficient, it can be clearly seen which influencing factors are dominant and which influencing factors are secondary, so as to facilitate engineers and technicians to measure and control each influencing factor in a timely and accurate manner.

Yang Liyu; ZHANG Yongfeng; Xu Xiangwei; etc

Abstract:
In order to integrate the advantages of parametric and nonparametric models, the application of semiparametric regression model in power load prediction is studied. On the basis of the original data preprocessing, the correlation analysis theory was used to determine the parametric and nonparametric variables in the semiparametric model, and the semiparametric regression model was constructed. The regression coefficients and regression parameters were estimated by using the two-stage least squares method and the weight coefficient method. The example results show that the semiparametric regression analysis method has high load prediction accuracy and wide application range.

CHEN Genyong; General Hou Yong; Yang Fengmin; etc

Abstract:
Aiming at the single-phase ground fault current increase and overvoltage after grounding in 20 kV urban cable distribution network. The neutral grounding method suitable for different network structures of 20 kV power distribution was studied. Through the 20 kV distribution network neutral point ungrounded, arc suppression coil grounding, resistance grounding three ways and ground fault steady-state analysis, transient analysis and system parameter analysis. Compared with the grounding mode of 3 kV distribution network, it shows the application range of the grounding mode of 10 kV distribution network, and the neutral point ungrounding method can be used when the system capacitor current is less than 20 A. When the system capacitance current is between 10~10 A, the arc suppression coil grounding method can be adopted; When the system capacitance current is between 15~100 1 A, the low resistance grounding method can be used; Example analysis shows that the neutral point is grounded with low resistance in the 000 kV cable distribution network.

Xiao Junming; FAN Fuling; LI Yanbin; etc

Abstract:
In the production process of yarn, tensile performance testing is an important process. In order to improve the grade and quality of finished products, the microcomputer measurement and control system of yarn tensile testing machine was developed. The system is composed of host, tensile measurement sensor, extension measurement sensor, automatic return positioning unit and upper computer, the host adopts 77E58 single-chip microcomputer, adopts high-precision A/D converter, and the rate is up to 100 times/s; Maximum load 1 kN; Minimum value 0.01 N; Accuracy class: 0.1 grade; Test speed range 0.005~500 mm/min; Displacement measurement accuracy: within ±0.1% of the indicated value; Displacement measurement resolution: 0.01 mm. The test shows that the system has high detection accuracy and fast data processing speed, and can be used with various tensile testing machines used in building materials, textiles, metal products, paper products and other industries, and has a good promotion and application prospect.

Su Zhijian; WANG Rui; Zhu Gaojie

Abstract:
A method for generating three-dimensional topographic maps from contour topographic maps is proposed. Firstly, the contour topographic map is digitized, the discrete point elevation data is obtained, and the digital elevation model is obtained by kriging interpolation. Then use Visual studio 2008 as the development platform and VTK (Visualization Toolkit) as the tool to generate three-dimensional terrain; Finally, an example is used to verify the effectiveness of the proposed method.

Wang Zhongyong; ZHANG Zhenxing; DUAN Linlin; etc

Abstract:
Aiming at the abnormal state of a certain type of naval gun follow-up system, a fault diagnosis expert system based on fault tree is designed and implemented. Firstly, the composition of the expert system for naval gun fault diagnosis is given, and the design methods of knowledge base, reasoning machine and human-machine interface module are mainly introduced. According to the characteristics of the fault of this type of naval gun, the fault tree is constructed, and the knowledge base is built and updated. The inference machine adopts an inference strategy combining forward inference and inverse reasoning. Practice shows that the fault diagnosis expert system has beautiful human-computer interaction interface, convenient user operation, basic reliability of fault diagnosis results, and easy expansion of knowledge base.

ZHOU Qinglei; Wu Xiaoying

Abstract:
The authentication test method based on the string space model has certain limitations in analyzing the security of the protocol, and can only analyze a limited number of protocols. Therefore, the authentication test method based on the string space model is extended, the method is improved by modifying the test components and authentication test rules, and the TLS protocol using signature and hash functions is analyzed by the extended authentication test method, and the scope of use of the authentication test method is expanded. And the test of the freshness of the test component is proposed, and the certification test method is further improved.

ZHANG Aimei; Kong Wenjie

Abstract:
Aiming at the uneven distribution of vehicles in each traffic direction of road intersection, such as in the suburbs of the city or the intersection of main roads and non-main roads, a design scheme of intelligent control system of traffic lights with DSP embedded system as the hardware platform is proposed. The system uses CCD cameras to collect video images reflecting the road traffic scene, and then performs a series of processing on the obtained video images, and uses background subtraction to quickly obtain the vehicle information of each phase of the road intersection, and then controls the time and change of the corresponding traffic lights in real time according to the number of vehicles in each relative phase, so as to realize the adaptive control of traffic control signal lights. The test proves that the system has the characteristics of good real-time performance and flexible expansion.

Mu Xiaomin; ZHAO Haifeng; Yang Shouyi

Abstract:
A parameter estimation method based on the cyclic stationary characteristics of SIMO (Single-Input Multi-Output) is proposed, and the cycle spectrum analysis of the DSSS signal after sub-integration is carried out, and the planting frequency and code element width of the signal are estimated. Simulation results show that . This method can make full use of the spatial diversity provided by multiple antennas to improve the parameter estimation performance of DSSS signals.

Ju Xingang; Guo Haiou; Guo Min

Abstract:
Taking the algorithm design of ethanol gas detector as an example, the radial basis neural network was used to fit the calibration data obtained from 34 groups of ethanol gas concentration detection experiments, that is, the network design and simulation analysis were carried out by using the radial basis function in the Matlab environment. The results show that the algorithm based on radial base network has small data storage and good error performance, which meets the error requirements of the system, and the training time of the network is short and the convergence speed is fast.

ZHANG Junfeng; HAO Jiping; Li Tian

Abstract:
The virtual work increment equation of three-dimensional sorghum column element based on UL method is given, the geometric nonlinear tangent stiffness matrix of three-dimensional space beam column element considering the effects of warpage and shear deformation is derived in detail, and the plastic surface of Orbison section is modified to consider the influence of torque and warpage on section strength, and the elastic-plastic tangent stiffness matrix of the element is derived by plastic flow method. According to the object-oriented programming idea, the entire finite element domain is divided into 8 basic classes, a new unit class is derived on the basis of the unit base class, and the object-oriented space steel frame analysis program is compiled in C++ language. The example proves that only one or two units are needed to accurately predict the ultimate bearing capacity and instability mode of the empty steel frame.

HOU Ying; Hoda

Abstract:
Combining the gradient optimization method with the finite element method, the implicit functional function reliability algorithm is discussed, the main failure modes of the stiffness of semi-rigid and rigidly bonded steel frame systems are compared and analyzed by example, and the influence of joint rotational stiffness and P-△ second-order effect on the stiffness reliability of structural systems is discussed by PNET method. The results show that the main failure modes of the system stiffness of the semi-rigid joint and the rigidly connected steel frame are basically the same, and the large displacement between the layers forms the main failure mode of the stiffness of the structural system. The semi-rigid connection has a great influence on the stiffness reliability of the structural system, and increases the influence of the P-△ second-order effect.

Pi Suping; Shi Gang; Gao Guangyun

Abstract:
Aiming at the ground vibration problem caused by train operation on saturated foundation, the interaction force between track and roadbed is calculated by using the train-track finite element model, and the excitation load is calculated by ground vibration after Fourier transformation. On this basis, combined with the saturated foundation dynamic Green function obtained by the thin layer method, the ground vibration generated under the traveling conditions of the train on the saturated foundation was calculated and evaluated. The results show that the train speed has a great influence on the vibration within a certain range. The ground vibration caused by the train can basically meet the vibration standard of residential areas at the near track.

Mo Shixiu; Guo Yueqin

Abstract:
The enthalpy model was used to establish the temperature field of frozen soil subgrade with phase transition. The influence of subgrade height, subgrade construction season and other factors on the optimal burial depth of the insulated board was comprehensively analyzed by considering the short-term and long-term permafrost protection effects, and considering the short-term and long-term permafrost protection effects. The finite element calculation showed that when the construction season was delayed to the cold season by 3 months, the frozen soil protection effect of the insulation board was significantly enhanced, and no melt core appeared in the roadbed within 20 years of operation. When determining the best burial depth of the heat insulation board, it is necessary to comprehensively consider the influence of the construction season, the height of the roadbed and other factors, if the roadbed is low, it should be shallow burial, the height of the roadbed is high, the warm season construction should be buried in the middle, and the cold season construction should be shallowly buried.

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