2008 volumne 29 Issue 04
Hong Jiawang; Fang Daining
Abstract:
Based on the Jandau-Ginsburg-Devonshire (LGD) theory, a theoretical model of ferroelectric nanowires is established, and a new method for obtaining exterior elongation is established by comparing with the first-principles calculation results. For Pb(Zr0Ti5.0)5,(PZT) nanowires, the exterior elongation is 0 nm. The calculation results show that there is a critical diameter of O.20 nm in the PZT nanowires, and the inhibition of the surface effect of the nanowires on their ferroelectric properties is revealed.

LI Bin; LI Guiren; ZHOU Xizeng; etc
Abstract:
According to the periodic structure of the two-dimensional photonic crystal, the antenna signal in mobile communication is compensated, and for the electromagnetic wave, the dielectric constant contrast is like the periodic potential of electrons in the crystal. Based on the electronic micrography, the metal oxide compensation material made by substrate etching technology through photoresist is pressed into a thin film structure, and the periodic arrangement structure formed by two-dimensional photonic crystals is used to make thin film materials. Filter the RF ferry. The electric field distribution on the surface of the dielectric layer can be obtained by the boundary conditions, and the TE wave and TM crossing of the material surface are analyzed separately. The traditional optical crystal compensation structure is realized through common materials and mature manufacturing technology, which reduces the deviation formed by the antenna in different directions and enhances the corresponding polarization transmission intensity.

DONG Guobo; ZHANG Ming; DONG Peiming; etc
Abstract:
Pure phase CuLaO2 powder was prepared by traditional solid phase sintering method, and CuLaO2 film was prepared by RF magnetron sputtering method for the first time and annealed, and CuLaO2 film with a small amount of heterophase was obtained. Its transmittance is higher in the infrared light region, nearly 70%, and the visible light is lower in the Itt phase.The conductivity of CuLaO2 film is about 6.7×10-4S/cm.The photoluminescence performance of CuLaO2 powder and film at room temperature was compared and analyzed.The test results show that the powder and film have obvious luminescent bands in the range of 450 am-650 am, while the film has a small amount of heteropeaks, which are due to the influence of La203, Cu oxide and quartz substrate.

SUN Xiaofeng; Ma Shining; Zhu Naishu; etc
Abstract:
Four typical nanomaterials were selected as microwave absorbers to study their effects on the curing time and mechanical properties of modified epoxy Vitex under microwave action. The results show that under the same curing conditions, the microwave curing time of the modified epoxy adhesive can be significantly reduced. With the increase of the amount of addition, the curing time is greatly shortened, among which nanoFe and nano siOx are particularly prominent. When the mass fraction is added more than 4%, the curing time is less than 3 min. The mechanical property test shows that after adding nano-Fe and nano-Fe5)3, the tensile strength and elastic modulus of the adhesive after microwave curing have no significant change, and when the mass fraction is added to 4%, the tensile strength is 4.33 MPa and 8.34 MPa, respectively. After adding nano-siOx and SiC, the tensile strength and elastic modulus values decreased slightly.


WU Xiao; Tang Jingyuan; ZHANG Yongcai; etc
Abstract:
At room temperature, ferric chloride (FeCl3·6H2O), sodium acetate (CH2COONa) and acetylacetone were used to obtain ferric acetylacetonate (Fe-(ACAC)3) solid powder by simple precipitation reaction, and used as a precursor to prepare pure Fe20O80 (magnetite) nanocrystals by hydrothermal treatment at 160-12 °C in 3% hydrazine hydrate for 4 h, and the structure and composition of the product were prepared by various modern analytical and testing methods such as XRD, TEM, VSM, FTIR and Raman spectroscopy , morphology, size and magnetism were characterized, and the possible synthesis mechanism of the product was discussed.

XU Jingjing; Ao Yanhui; Fu Degang; etc
Abstract:
V-doped TiO2/activated carbon(AC) photocatalysts were prepared by hydrothermal method under mild conditions. XRD, SEM, diffuse reflectance, infrared and fluorescence spectroscopy were used to characterize the physical and chemical properties of the catalyst. The results show that V-TiO2 still maintains the anatase phase without the diffraction peak of V. Compared with pure TiO2, V-doped samples have higher surface hydroxyl density, lower planter recombination probability, and the absorption spectrum shifts to the visible region. Nanoscale V-TiO2 can be deposited on AC to form micro-nano structures. Under visible light irradiation, V-TiO2/AC catalytically degraded 4-chlorophenol was higher than pure V-TiO2 and P25, which could be attributed to the doping of V and the synergistic effect of AC.


Qu Huimin; KONG Ying; ZHANG Yuzhong; etc
Abstract:
Polyvinylidene fluoride was used as the base film material and hydroxyethylcellulose (HEC) was used as the active layer material, and the mass concentration of wattle was added to the bottom film casting solution. Different HEC composite membranes for pervaporation desulfurization were prepared; The desulfurization performance of the composite membrane was evaluated by catalytic cracking gasoline, and the mass transfer of gasoline components in the bottom film was simply analyzed. The results show that . The mass concentration of the additive increased, the average pore size of the bottom film increased, but the porosity decreased slightly, but the mass transfer coefficient of the gasoline component in the bottom film increased. The concentration of additives increased, and the selectivity of HEC composite membrane for sulfides first increased and then decreased. The permeability decreases first and then increases, and an extreme value occurs when the amount of wattle is added by 1%.


XU Linhua; Lee Sang-eun; Yuan Jun
Abstract:
Fe-doped ZnO films were prepared on quartz glass substrates by sol-gel method, and the effects of different Fe-doped concentrations on the microstructure and optical properties of ZnO films were studied. X-ray diffraction was used to analyze the crystal orientation and crystal phase of thin film samples. The surface morphology of thin film samples was observed by atomic force microscopy, and the optical properties of znO thin film samples were analyzed by dual-beam UV-Vis spectrophotometer. The experimental results show that all ZnO film samples have hexagonal zinc structure, and ZnO grains grow optimally along the c-axis. After the incorporation of 1% fe with a mass fraction, the C-axis preference orientation of ZnO films was further enhanced, and the crystallization quality of the films was further improved. When the doping concentration of Fe is higher than 1%, the intensity of the diffraction peak of ZnO film (002) decreases, which may be due to Fe2+ (x=2 or 3) and zn2+ having different ion radii, and a large amount of Fe2+ enters the lattice to replace Zn2+, resulting in severe distortion of the lattice, thus affecting the normal growth of znO grains. The prepared ZnO films have high transmission abundance in the visible region, and the optical band gap of ZnO films estimated by the absorption edge shows that the optical band gap gradually widens with the increase of Fe doping concentration.

Wang Hongxing; LIN Pinghua; Reserve Forest; etc
Abstract:
Low hardness and poor wear resistance restrict the application of copper in the field of metallurgical equipment. In order to improve the surface hardness and wear resistance of copper metal, the nickel-plated slurry clad chromizing technology is used to chromize the copper surface. The chromium-infiltrated layer was prepared, and its microstructure, diffusion characteristics, microhardness and wear resistance were studied. The results show that after nickel plating and chromium plating on the copper surface, a 50μm chromium permeated layer is obtained on the surface of the nickel layer, and the structure of the permeable layer is a nickel-chromium solid solution phase. The hardness of the permeable layer gradually decreased from 345 HV in the outer layer to 120 HV in the nickel coating and 70 HV in the copper matrix, and the microhardness of the permeable layer decreased with the decrease of chromium content. Chromium permeation reduces the coefficient of friction of copper and nickel from 0.8 and 0.6 to 0.45.


Zheng Xuejing; JOACHIM LOOS.
Abstract:
Low-pressure scanning electron microscopy (LVSEM) was used to characterize the morphology of MgCl2-supported zjegler-Natta catalyst and very low-yield polypropylene particles.MgCl2 air is very sensitive, and exposure to air for more than ten seconds is enough to affect the morphology of Vitex. LVSEM can obtain high-resolution images at low incident voltages such as l keV. At low incidence voltages, no charge buildup occurs on the sample surface. Therefore, there is no need to spray the sample with a conductive layer. Due to the greatly shortened contact time with air, LVSEM can avoid the interference of air on the morphology of the sample, and become a powerful means to characterize the morphology of Mgcl2 negative planting catalyst.

ZHOU Cairong; SHI Xiaohua; Cheng Chunyan

Abstract:
In this experiment, biodiesel was prepared from vegetable oil by microwave method on the basis of traditional transesterification method, and the process conditions were optimized. The new process shortens the reaction time and improves the yield of biodiesel. When cottonseed oil is used as raw material, the best process conditions for transesterification reaction are: molar ratio of alcohol oil 6:1. reaction temperature 60 °C, reaction time 60 min, catalyst dosage of 1% (wt).

Ren Hui; Zhou Zhenhong

Abstract:
How to correctly call the Win32 API functions provided by the Windows operating system to extend Visual Fortran’s functions in window management, memory management, drawing, multithreading, etc., is a problem often faced by the current numerical computing WineIOWS application development. This is discussed more systematically, including how the Win32 API interface modules provided by Visual Fortran are organized. How the interfaces are encapsulated, how to set consistent strings, pointers, and structures according to the interface definition, Fortran arguments, etc. And illustrate with typical examples. Provides how-to instructions for Win32 API function calls on the Vis-ual Fortran platform.

Feng Dongqing; Li Fengguang; HUANG Junjie; etc

Abstract:
In order to realize the online monitoring of the working state of the rail switch machine, a new power sensor device is designed. The device is based on the high-speed, assembly line structure MCU system, combined with the high-precision three-phase power special chip ATT7022 with DSP core, which constitutes the core part of the device. Considering the harsh working environment and large interference of the system, the necessary anti-interference design is carried out by the vegetable market power supply, signal acquisition channel and signal output channel, which realizes the characteristics of high precision, low power consumption and strong anti-interference ability.

Yao Zhenya; Zheng Juanrong; Liu Lina

Abstract:
The chemical shrinkage or expansion of alkali-jerked cementitious material and water-cement system was experimentally studied, and the water-cement system was used as a contrast sample. The results showed that chemical shrinkage occurred in the water-cement system, alkali-excited slag and alkali-excited fly ash system at room temperature (20±1)°C, and the shrinkage value increased with the extension of reaction age. The chemical shrinkage of the water-cement system is greatest at the same age. The chemical shrinkage of alkali-excited slag systems is minimal; Chemical expansion occurred in alkali-inspired metakaolin system, and its expansion value increased with the extension of reaction age. The reaction product of alkali excitation metakaolin is amorphous zeolites (because of the NH4+ ion exchange properties of zeolite), in which the products with low polymerization degree contribute greatly to chemical expansion; The properties of the main reaction products of alkali-excited slag system and alkali-excited fly ash system are similar to those of cement products, but there is a small amount of amorphous zeolite, which partially counteracts chemical shrinkage.

ZHANG Zhifeng; ZHANG Changbo; Feng Zhongxu; etc

Abstract:
Taking SUP16 asphalt mixture as an example, the performance analysis and experimental study of asphalt mixture with different segregation conditions in on-site construction were carried out, and the relationship between aggregate segregation and temperature segregation of asphalt mixture and the change of void ratio, as well as the influence of void ratio on the compaction and flatness of asphalt pavement, were analyzed. The results show that the average porosity of coarse aggregate concentrated mixture is 9.5, and the water absorption rate is as high as 2.0, and the effect of coarse aggregate segregation on the performance of asphalt mixture is more serious. The change of porosity is obviously affected by the temperature of the asphalt mixture. The amplitude increases with the decrease in temperature. The deviation between the porosity and the design value increases. The compaction quality and flatness of the pavement deteriorate.

LIU Lixin; TIAN Gaoyan; ZHAO Wenlan; etc

Abstract:
The experimental study of continuous shrinkage deformation of perforated concrete bricks that have just been molded for 100 days was carried out. The effects of ambient temperature, relative humidity and age on shrinkage and deformation of concrete perforated bricks under standard conservation and natural conservation environmental conditions were analyzed. An estimation formula for shrinkage deformation of concrete porous bricks considering these factors is proposed. This study result can provide a reference for solving the problem of wall cracking in concrete perforated brick engineering in China.

WANG Xinling; ZHU Juntao; Lv Lin; etc

Abstract:
Taking a frame structure of a two-story reinforced concrete industrial plant as the prototype, according to the 1:3 scale model, the reinforced concrete frame specimen was designed, and the sorghum ends, column ends and nodes of the frame were reinforced with carbon fiber cloth, and then the frame was tested with horizontal and low cycle repeated loads. Based on test results. The crack development, seismic resistance and failure characteristics of the reinforced concrete frame specimen reinforced with carbon fiber cloth reinforced in good condition were analyzed, and the hysteresis curve, skeleton curve and hysteresis curve of column end steel bar and CFRP cloth were drawn. The seismic performance of the concrete frame structure reinforced with carbon fiber cloth was studied. The test results show that the concrete frame structure with good carbon fiber cloth reinforcement has good seismic performance and hysteresis energy dissipation capacity.

Shi Yanghang; Yuan Shuangxi

Abstract:
Aiming at the remarkable characteristics of fly ash and its wide application in engineering, the time engineering fully investigates, analyzes the material composition and designs the mix ratio. The water-to-adhesive ratio, fly ash content and sand rate were used as the changing parameters. The orthogonal test method was used to conduct experimental research on high content fly ash concrete, and the influencing factors were analyzed in depth. The results show that . The water-to-adhesive ratio and fly ash substitution rate are the main factors affecting the performance of concrete, and the sand rate has a great influence on the fluidity and strength of concrete. At the same time, the correlation between the influencing factors and the concrete properties under the condition of high fly ash content and its variation law are obtained, which can be used as a reference for theoretical research and engineering practice.

Liao Zebang; HUANG Bencai; Lin Gao

Abstract:
In order to verify the feasibility of numerical simulation in the application of average wind pressure of large-span closed roof, the average wind load of the comprehensive gymnasium of Shenyang Olympic Sports Center was analyzed by numerical simulation method, and the total lift and average wind pressure distribution of different wind downwards on the roof were obtained. The regularity of total lift with wind direction was analyzed, and the average wind pressure distribution was compared with the wind tunnel test results. It can be seen that the results of the two methods on the roof with eaves on three sides are similar, indicating that the numerical simulation method is feasible to simulate the average wind pressure distribution of the closed large span roof. By comparing the cantilevered edge and the circular arc edge, it can be seen that the SST K-w turbulent flow physical model has good accuracy in calculating the flow field dominated by separated flow. Finally, the characteristics of the distribution of cones on different forms of eaves roofs are studied.

Li Peilong; ZHANG Zhengqi; Wang Binggang

Abstract:
In order to study the behavior and mechanism of asphalt ultraviolet aging, two kinds of bitumen were used for indoor simulated photoaging test. Through the analysis of viscosity and ductility time ratio of bitumen at different aging times, the decay behavior of high and low temperature performance of asphalt UV aging was studied, and the microscopic changes and aging mechanism were discussed by component test, colloidal structure and infrared spectroscopy(IR) analysis. The results show that UV aging mainly occurs on the surface of asphalt, resulting in a significant attenuation of the low temperature performance of asphalt. The effect on high temperature performance is relatively small; The aromatic components and gums in bitumen are sensitive to ultraviolet light. It is easy to generate asphaltenes by photooxidation reaction, the colloidal instability index and relative carbonyl index are increasing, and the asphalt properties are constantly deteriorating.

Qin Li; JIA Xiaogang; Yang Yanbo

Abstract:
Due to the improper layout of the shear wall, it is not uncommon for the structure of the special-shaped column and frame shear wall in service to undergo serious torsional deformation or even collapse under the action of earthquake. By adjusting the shear wall layout scheme in the actual engineering of a special-shaped column frame and shear wall structure, the author carried out modal analysis and elastic time history analysis of the improved model, and studied the influence of different plane arrangements of shear wall and special-shaped column on seismic response. It is found that the seismic performance of the improved model is significantly improved, the bottom shear force does not change much, the maximum floor displacement and structural self-resonance period are significantly improved, the maximum floor displacement value is reduced by 14.4%, and the self-oscillation period is reduced by 4.34%.

ZHANG Kai; LI Yu; Zhou Yan

Abstract:
Most of the old rigid arch bridges in service are seriously damaged, taking a canal bridge on the 327th line in Shandong Province as an example. Combined with the structural characteristics of steel frame arch bridges. The static and dynamic mechanical properties were analyzed by the space finite element method, and the force characteristics and damage failure mechanism were discussed. It is revealed that the old rigid arch bridge designed according to the old code has insufficient bearing capacity and is in urgent need of reinforcement and maintenance. The analysis results provide a basis for its performance evaluation, and provide reliable technical data for the continued safe use, maintenance, reinforcement, reconstruction or restriction of bridge traffic, and the results can be used for the analysis of other similar bridges.

Wang Ti; Huang Pingming

Abstract:
Elastic connection devices and dampers are set up at the tower and beam connections of Sutong Bridge. The elastic stiffness and damper parameters of the appropriate elastic connection device were selected, the hysteresis energy dissipation characteristics of the viscous damper were simulated by Maxwell damping model, and the shock absorption effect of the elastic connection device and the viscous damper was compared by the method of structural nonlinear seismic analysis, and the analysis showed that the elastic connection device and damper could effectively reduce the seismic displacement of the beam end, but the effect of the damper was more ideal.

SUN Fangjin; ZHANG Daming; Yin Zhixiang

Abstract:
Combining image recognition technology and neural network (ANN) system, a simulation method for wind load of large-span structure is given. Two image recognition technologies, recursive graph and feature face recognition, are used to convert the wind speed time numerical series into image information. Then, a large number of wind speed time series are converted into vector Ω with fewer dimensions, and then combined with the multi-layer ANN system to obtain a simplified neural network model to predict the wind speed time history of each point in space. Finally, it is applied to the wind load simulation of a large-span structure, and the results not only conform well with the target value, but also reduce the number of layers of the neural network, and greatly improve the operation speed and the credibility of the results.

Mei Gang; Xu Nengxiong

Abstract:
An optimization design method based on the lateral shift control of pile top during construction is proposed, and an optimization design model is established. In this method, the lateral movement of the pile top during excavation of the foundation pit is taken as the optimization goal, and the distance from the anchoring point to the pile top is the optimization variable. The intersection point of the primary displacement and the quadratic displacement curve is used as the optimization point to determine the optimal position of the anchor, and then the pile anchor support structure is optimized. According to the above optimization design method and model, the optimization design system is developed using VB language, and the engineering case analysis is carried out, and the design results show that the optimization design system is feasible and the optimization design method and model are reasonable.

Ren Zhiyong; Sui Dan; Ge Lindong

Abstract:
A new algorithm based on wavelet multi-resolution analysis is discussed, which can be directly implemented for IF signals without the need for known carrier frequency and system synchronization. Simulation results confirm the effectiveness and advantages of the algorithm over other algorithms.

Xiao is webbed; Xiao Yougang; Lei Xianming; etc

Abstract:
By defining the sliding yield function and the flow potential function of the contact surface, the complementary equation of the thermal contact boundary is obtained. Based on the principle of virtual work and the contact element technology, the finite element equation of the three-dimensional elastic contact problem under thermal stress is derived, and the contact pseudo-load is introduced into the equation to reflect the influence of the contact state change on the load planting. In the process of shading solving, the strategy of accelerating every two iterations is adopted, which significantly improves the solution efficiency.

HU Junping; ZHANG Ling; Shi Tianliang

Abstract:
Through the analysis and research of the lifting system of hydrostatic pile press, the simulation model of hydraulic drive system was established by using AMESim software, and the mechanical equation of the wire rope was established, and the influence of excitation acceleration on the dynamic tension of the wire rope was analyzed. The relationship between the maximum lifting capacity of the lifting system and the maximum oil pressure of the luffing cylinder and the luffing angle of the boom under different moving coefficients is carried out. Through simulation analysis, it can be seen that the change of excitation acceleration will cause the change of dynamic tension, and the modified dynamic load coefficient is used instead of empirical value to analyze the model mechanically, which not only simplifies the calculation process but also makes the results more accurate.

Wang Zhe; Xia Hongshan

Abstract:
In view of the fact that the new airport lacks historical data, the entropy weight method is used to determine the weight of each economic index. The comprehensive evaluation index of the city where the analogous airport is located is calculated based on the weight of each index, the analogy prediction method is given, and the throughput and future growth rate of the new airport are calculated according to the comprehensive evaluation index of the analogous city. Taking Jiuzhaigou Huanglong Airport as an example, an empirical analysis and research on the analogy prediction method is carried out.

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