bluuebunny/crossref_metadata_2025 huggingface dataset:
System of Lifting and Lowering Base Plate Used in Deep-Water Exploration Ship
Authors: Yang Yan Gui , Chen Zhi Xin , Lu Min Xun , Xu Zhi Qiang
Published: March 2013

This paper presents a new scheme of lifting and lowering base plate used in deep-water exploration ship. The scheme with a wire rope and two fixed pulley acted as rotary lifting points ensures that the base plate can be lifted or lowered when one of the two winches breaks down. A closed circuit system is designed to actuate two winches to lift or lower the base plate. The working principle and characteristics of the hydraulic system was described. The parameters of components in the closed circuits were calculated according to the design conditions and design requirements given. Finally, the hydraulic equipment based on the hydraulic system was tested by using a simple test setup. The results of the test indicate that the hydraulic equipment meets the design requirements.
Simulation and Optimization of Absorption Column of the Dual-Pressure Nitric Acid Production Process
Authors: Liu Ji Dong , Dong Zhong Zhe , Xu Jian Xin , Guo Ai Kang , Tian Zhi Liang
Published: March 2013

Simulation of the absorption column was studied. A new mathematic model was developed and tested against the actual operation data. From this, the accuracy of the model was proved. The pressure, temperature and gas composition on absorption effect was discussed. And from the point of the practical production, more optimized operating conditions of the nitric acid absorption tower were showed. It makes the dilute acid concentration increase by 3 percent and the exhaust emission of NOx decrease by 45ppm.
Design of a Three-Axis Digital Output Gyroscope-Based Intelligent Ultrasonic Diagnostic Navigation System
Authors: Xu Tian , Tian Hong Er , Zhang Chi Min , Shen Hui Ming , Sun Yi Xin , Fu Jian
Published: March 2013

In this work we reported a design and principle of a three-axis digital output gyroscope-based intelligent ultrasonic diagnostic navigation system. The proposed system provided a real-time intelligent navigation for ultrasound scanning and clinical puncture by transmitting and recording the positional relationship of ultrasound probe and corresponding body structure in real time through network. This system could provide technical support for remote ultrasonic medical consultation.
Simplified Calibration of Resistive Pressure Sensor Based on ZMD Chip
Authors: Wang Zhong Ming
Published: March 2013

In order to eliminate the negative effect of temperature to resistive pressure sensor of automobile, a calibration circuit is required based on ZMD chip or MAX1452. The traditional calibration way of ZMD is four-point calibration that has the defects such as inefficiencies and complexity. Thus, a simplified calibration way, named as three-point calibration, is provided which is able to simplify the calibration equipment in practical manufacturing. Considerably, the calibration efficiency is improved from about one hour into 5 minutes every time. After calibrated, the output of pressure sensor change only with pressure and the deviation value is from -0.48%FSO to +0.84%FSO，in the designing range ±2%FSO.
Constructing the Knowledge Base of Training Experts for Power Network Dispatching Operation Mode
Authors: Qian Feng , Fan You Ping , Ai Yun Fei , Liu Chen
Published: March 2013

We combined the realism of power network, applied knowledge associated with management of knowledge and human resource to classify and summarize the multifarious data, information and professional skills of power network dispatching operation mode, and then graded the classified and summarized knowledge to make different level of training system for different level of dispatching operation mode personnel. Scientifically reasonable training system would give an incentive to transform dispatching operation mode personnel from being subject to knowledge to being beneficial from it, so that well promote the gird operation stability, reliability and economic.
Construction of Practice Environment to Cultivate High-Quality Technical Talent
Authors: Yang Zhi Ping , Wu Wei Long
Published: March 2013

To meet the mechanical and electrical engineering field requirements for the excellent high-quality technical talent, the research constructs the practice environment to cultivate high-quality technical talent, fulfills system operation of the practical environment to train the high-quality technical talent, creates operating platform to train the high-end talents with excellent skills, proposes the idea of the coordinated development to train the high-end excellent skill talents based on practical environment, provide the ways of connected between the excellent skill talents with the social, and develop the approaches to service full range of industry. The research results are suited to reference for similar vocational training system.
Cost-Optimal Operation of Heat Exchanger Network Considering Pressure Drop Constraints
Authors: Zhao Liang , Huo Zhao Yi , Mu Lin , Yin Hong Chao
Published: March 2013

Considerable research effort has been reported in cost-optimal operation of heat exchanger network. However, most of them neglect the pressure drop influence and assume constant film heat transfer coefficients. Pressure drop of streams are important influencing factors for the performance of heat exchanger network operation. In this paper, a general cost-optimal operation model considering pressure drop constraints and removing the assumption of constant film heat transfer coefficients is proposed. It is necessary to determine the pumping power cost required as part of operating cost function. The extended model is applied to one example taken from previous research, and the results prove that the proposed method can obtain more real optimization results for HEN operational optimization problems.
Influence of pH on the Antioxidative Activity of Maillard Reaction Products Generation from Model Reaction of L-Ascorbic Acid and L-Lysine/L-Methionine
Authors: Deng Qi Hui , Yu Ai Nong
Published: March 2013

Maillard reaction products (MRPs) were prepared by heating the solution containing L-ascorbic acid (ASA)and L-lysine (Lys)/ L-methionine (Met) adjusted to various pHs (4.0, 5.0, 6.0, 7.0 and 8.0) at 140±2°C for 2 h. The browning, intermediate products, reducing power and DPPH (1,1-diphenyl-2-picryl-hydrazyl) radical-scavenging activity reached a maximum with initial pH 5.0 (P < 0.05). Thereafter, slightly differences with initial pH of 7.0 and 8.0 were found. An increase in Ferrous ion chelating activity of MRPs derived from ASA-Lys/ Met model systems, as measured by absorbance at 562 nm, was observed as the initial pH increased (P < 0.05). In general , antioxidative activity of ASA-Lys/ Met MRPs was coincidental with the browning development and the formation of intermediate products.
On Applications of Generalized Intelligent Control System Synthesis Method Based on Idea of System Generalized Performance Index
Authors: Han Zhong Xu , Chen Ya Hong
Published: March 2013

Every control theory has its advantages and shortages. It is difficult to adopt single control theory or method to solve technical problems of complex control system. Taking asymptotically tracking and disturbance rejection of complex controlled object as an example, the Reference is to explore noetic method of control science, and approve the control ideas of broad the nonlinear control system performance indicators Receiving the thought of metasynthetic engineering, a generalized intelligent control system has been designed by fusing manifold control ideas, which is beneficial to bring colony wisdom into play and is accordance with opening great system study pattern, and is expansible. There has presented sufficiency conditions and proves of the system stability, and salience effect has been acquired in engineering practice.
The Study and Application of Gaussian Process Surrogate Model Based on Gradient Particle Swarm Optimized Hyper-Parameters
Authors: Xia Wei , Pan Hong Chen , Liao Xiao Ping
Published: March 2013

Constructing a high-fidelity surrogate model to optimize production process is often required to meet the requirement of manufacturing process programming ,one of the most popular techniques for the construction of such a surrogate model is that of Gaussian process surrogate model. In this paper, the development of a gradient particle swarm optimization is described, which aims to reduce the cost of this likelihood optimization by drawing on an efficient adjoint of the likelihood, and improve the precision of the model. A multimodal benchmark function was used to test, show that the tuning strategy can provide an accurate Gaussian process surrogate model. Based on LHS ,Gaussian process surrogate model (GP) and gradient particle swarm optimization algorithm (GPSO), a optimization model which is used for improving the quality of Al profile welding is built and utilized to obtain optimal multi-parameters of Al alloy proﬁle extruding processes and moulds. Optimal solution is validated by experiment.
Stable Computer Control Algorithm of Von Neumann Model
Authors: Wu Xiu Mei , Si Tao Zi , Jiang Lei
Published: March 2013

The problem of computer control algorithm for the singular Von Neumann input-output model is researched. A kind of new mathematic method is applied to study the singular systems without converting them into general systems. A kind of stability condition under which the singular input-output model is admissible is proved with the form of linear matrix inequality. Based on this, a new state feedback stability criterion is established. Then the formula of a desired state feedback controller is derived.
Liquid-Liquid Equillibria for the (Water + Methanol + Citral) System at 283.15 and 313.15 K
Authors: Huang Cheng , Li Heng De , Yan Yan , Han Yong Tao
Published: March 2013

Isobaric liquid-liquid equilibrium tie-line data were determined at atmospheric pressure and at 283.15 and 313.15 K for the mixture (water + methanol +citral). The miscibility for the ternary (water + methanol + citral) LLE was increasing as the temperature increased. The experimental liquid–liquid equilibrium data have been satisfactorily represented by using an extended UNIQUAC model.
Study on Thermal Isomerization of Isopimaric Acid
Authors: Chen Yu Xiang , Zhao Zhen Dong , Gu Yan , Lu Yan Ju
Published: March 2013

The thermal isomerization reaction of isopimaric acid was studied by a treatment at different temperature of 250 °C, 260 °C and 270 °C for 1-5 h under the protection of nitrogen. The isomerization mechanism of isopimaric acid was illuminated. Isopimaric acid was remarkably isomerized to 8, 15-isopimaric acid and sandaracopimaric acid, the higher thermal treatment temperature combined with longer thermal treatment time, the faster isomerization rate of isopimaric acid was observed. It was found that the isomerization rate of isopimaric acid towards 8, 15-isopimaric acid was faster than to sandaracopimaric acid. The decomposition reaction of pimaric-type acids occurred slightly in conditions of 250 ~ 270 °C.
Synthesis and Crystal Structure of the Lead(II) Complex with 5-Hydroxyisophthalic Acid
Authors: Yang Yan , Yan Liu Ting , Qin Rong Huan , Duan Wen Gui
Published: March 2013

The lead(II) Complex constructed with 5-hydroxyisophthalic acid, [Pb3(5-hipa)2]n•4H2O(1), (5-hipa = 5-hydro- xyisophthalic acid) has been synthesized by hydrothermal methods and structurally characterized by elemental analysis, IR and X-ray single crystal diffraction. In trinuclear symmetrical complex 1, Pb1 is four-coordinated, Pb2 and Pb3 are three-coordinated by 5-nitroisophthalic acid groups, respectively, which is further connected through intermolecular hydrogen bonds resulting in a three-dimensional (3D) network.
Effect of the Ration of Cu to Mn on the Activity and Stability of Copper-Manganese Mixed-Oxides for the Water Gas Shift Reaction
Authors: Zhi Ke Duan , Liu Quan Sheng , He Run Xia , Wu Fang , Zhang Ya Gang , Yang Li
Published: March 2013

The effects of Cu/Mn ratio on the activity and stability of Cu-Mn catalysts for the water-gas shift reaction (WGSR) were investigated. Activity tests showed that the Cu-Mn catalyst while the ration of Cu to Mn is 1:1 displayed higher activity and better stability than that of others catalysts. The BET , XRD and TPR results revealed that the Cu-Mn catalyst while the ration of Cu to Mn is 1:1 led to higher surface area, a more stable catalyst structure and suitable reduction performance, in turn leading to better catalytic behavior for the Cu-Mn catalyst.
Effects of Alkali and Alkaline Earth Metals on NOx Reduction in Coke Combustion
Authors: Chen Yan Guang , Han Hong Jing , Lu Jia , Li Dan Dan , Li Jin Lian , Liu Shu Zhi
Published: March 2013

A series of coke samples with loading alkali and alkaline earth metals were prepared by the impregnation method, the NOx emission were investigated in a silica fixed bed reactor in the combustion process of raw coke and coke modified by Na, K, Ca and Mg. The results show that Na, K, Ca and Mg play in-situ catalytic effects on the NOx reduction reactions. When the loading amount of Na2CO3 is 2.0%, the NOx reduction ratio was around 17.4%, when the loading of K2CO3 is 2.0%, the amount of NOx emission is reduced by 26.5%. When the loading of CaCl2 is 2.0%, the amount of NOx emission is reduced by 22.3%. When the loading of MgCl2 is 2.0%, the NOx reduction ratio is about 10.9%.
Influence of Synthetic Methods on the Acid Catalytic Activity of NZP Family Compounds Modified by Doping Aluminum
Authors: Du Ying , Zhu Lin Hua , Si Tian
Published: March 2013

A new type of NZP family compound CaZr4(PO4)6 was synthesized by sol-gel method and coprecipitation method respectively, and the acidity of CaZr4(PO4)6 was modulated by doping aluminum. The phase and pore structure of the samples were characterized by X-ray diffraction (XRD) and N2 adsorption-desorption, the acid catalytic activity of CaZr4(PO4)6 doped by Al were investigated by using alpha-pinene isomerization as probe reaction. The results show that CaZr4(PO4)6 doped with Al element synthesized by sol-gel method have regular mesoporous structure and weak strength acid site, therefore the catalytic activity on these samples for alpha-pinene isomerization is higher than that on the Al doping samples prepared by coprecipitation method.
Progress in Adjustment of Ionic Liquids Acidity Based on the Alkylation
Authors: Zhang Wen Lin , Du Wei , Wang Xiao Wen , Meng Nan , Shao Yong Jun , Li Chun Li
Published: March 2013

Acidity is a very important character of ionic liquids, which determines the application of ionic liquids in catalysis. In some cases, the adjustment of ionic liquids acidity becomes important and necessary. Focusing on acidic ionic liquids, researches on determination of acidity, application of acidic ionic liquids in alkylation, acidic adjustment methods and novel acidic ionic liquids were reviewed. Finally the development of acidic ionic liquids is discussed.
Reaction Laws and Macro-Kinetics of 4-Carboxybenzaldehyde Hydrogenation over Pd/TiO2 Catalyst
Authors: Gao Jin Cheng , Wang Ji Yuan , Du Wen Bin , Lin Ling , Zeng Chong Yu
Published: March 2013

The effects of temperature and hydrogen partial pressure on 4-Carboxybenzaldehyde (4-CBA) hydrogenation over Pd/TiO2 catalyst were investigated in a batch reactor. The results show that 4-CBA hydrogenation is a consecutive reaction. And 4-CBA hydrogenation to 4-hydroxymethylbenzoic (4-HMBA) is a reversible exothermic reaction. Meanwhile, a parallel reaction of 4-CBA decarbonylation occurs during the process. The hydrogenation rate of 4-HMBA is more sensitive to temperature and hydrogen partial pressure than that of 4-CBA. Macro-kinetics of 4-CBA reaction over Pd/TiO2 was obtained from the experimental data using the power-law kinetics model. The apparent activation energies of 4-CBA hydrogenation, 4-HMBA hydrogenation, 4-CBA decarbonylation and 4-HMBA dehydrogenation are 29.65 kJ/mol, 42.55 kJ/mol, 74.32 kJ/mol and 69.34 kJ/mol, respectively. The reaction orders with respect to 4-CBA and 4-HMBA are both first-order.
Solvothermal-Derived Nanocrystalline TiO2 Supported Co Catalysts in the Hydrogenation of Carbonmonoxide
Authors: Kongsuebchart Wilasinee , Methachittipan Apipon , Kongviwatanakul Thatpon , Praserthdam Piyasan , Mekasuwandumrong Okorn , Panpranot Joongjai
Published: March 2013

Nanocrystalline TiO2 with the average crystallite sizes of 9 and 18 nm were synthesized by the solvothermal method and employed as supports for preparation of Co/TiO2 catalysts for CO hydrogenation reaction with various Co loadings between 5-20 wt%. For a similar Co loading, the use of larger crystallite size TiO2 resulted in higher higher CO hydrogenation activities with no influences on the product selectivities. However, an optimum amount of cobalt loading that maximized CO hydrogenation activity of Co/TiO2 was determined to be at ca. 15 wt.% for both TiO2 crystallite sizes.
Catalytic Voltammetric Determination of Vanadium in Crude Oil at Carbon Nanotube Paste Electrode
Authors: Zheng Li , Zhang Ying
Published: March 2013

A catalytic voltammetric method for the determination of vanadium(V) at a multi-wall carbon nanotube paste electrode (MWCNT-PE) in a 4-(2-pyridylazo)-resorcinol(PAR)-bromate system is proposed. The voltammetric response of V(V)-PAR complex at MWCNT-PE was significantly enhanced because of a catalytic cycle consisting of electrochemical reduction of V(V) ion in the complex and subsequent chemical oxidation of the reduction product of V(V) by bromate. In pH 2.70 H2SO4 solution containing 5.0×10-6 mol•L-1 PAR and 3.0×10-2 mol•L-1 KBrO3 without any preconcentration, the linear sweep voltammetric peak current of the catalytic wave was proportional to the vanadium concentration in the range of 8.0×10-9 to 3.0×10-6 mol•L-1. The detection limit was 2.5×10-9 mol•L-1. Using the proposed method, the vanadium concentration in crude oil was evaluated and the results were compared with those of atomic absorption spectrometry.
Adsorption Property of Cu-BTC for Dibenzothiophene Sulfide
Authors: Bian Yang Yan , Tang Lei , Cui Qun , Wang Hai Yan
Published: March 2013

Cu-BTC was synthesized by hydrothermal method. Adsorption desulfurization performance of Cu-BTC for dibenzothiophene sulfide was investigated. The adsorption property of Cu-BTC for dibenzothiophene and 4-methyldibenzothiophene in stimulated diesel were compared by equilibrium and dynamic experiments. The results show that when the equilibrium concentration is 0~50 mg S/L, the adsorption capacity of Cu-BTC for 4-methyldibenzothiophene is more than that of dibenzothiophene. When the equilibrium concentration is 50 mg S/L, the equilibrium adsorption capacity of Cu-BTC for 4-methyldibenzothiophene and dibenzothiophene are 17.54 mg S/gads and 15.64 mg S/gads, respectively. At the conditions of 30°C, 149.22h-1 and 0.1MPa, the initial concentration of dibenzothiophene and 4-methyldibenzothiophene is about 45.16~46.36 mg S/L, the adsorption property of 4-methyldibenzothiophene is superior than dibenzothiophene, the breakthrough capacity of Cu-BTC for 4-methyldibenzothiophehe is 1.73 times lager than dibenzothiophene. Cu-BTC shows an excellent prospect on diesel desulfurization process.
Chemical Equilibrium Prediction on Release of Na,K,Cl and S-Species during Gasification of Biomass, Soft and Hard Chinese Coal at Elevated Temperature and Pressure by Fact Sage
Authors: Jaffri Gul E Rana , Cen Ke Fa , Wang Zhi Hua
Published: March 2013

The release of alkali species can cause of severe problem of hot corrosion during gasification especially at high temperature and pressure. The direct use of coal may harmful for power plants. The aim of work to obtained comprehensive knowledge prior utilization of coal. Therefore, thermodynamic equilibrium calculations were performed by Fact Sage 5.2 and simulated the gasification environment at elevated temperature and pressure. Four hard and soft Chinese coal such as Yungui (Vad<6.6%), Xiao Tun(Vad<11.1), Datong (Vad <23.18), Ping Zhuan (Vad<31.84) ,and Saw dust (Vad<68.80) and Saw dust char (Vad<3.39) belongs to anthracite, Sub-bituminous, lignite, biomass and biomass char were selected and releasing order was calculated by plotting mole fraction of each species Vs temperature (1000 to 1400°C) at 1 bar and VS pressure (5 to 15bar ) at 1000°C. On the basis of predicted releasing order the H2S species can be predicted most stable species for gasification at elevated temperature and pressure. The high released amount of SO2, H2S, NaCl, KCl and HCl was obtained for YUN, DAT,SAD and SADChar at (1400°C-1000°C) temperature and (15-5bar) pressure. Comparing with high pressure the predicted release of KCl and HCl was observed higher but SO2, H2S, and NaCl release was found lower than elevated temperature during combustion process. The above available predicted information is valuable for development of hot gas cleaning technology.
Effect of Macropore Structure on Desorption Diffusion Performance of N-Pentane on 5A Zeolite
Authors: Shi Lu , Liu Zong Jian , Cui Qun , Wang Hai Yan , Yao Hu Qing
Published: March 2013

Desorption rate curves of n-pentane on 5A zeolites at 418 K and 10-0.03 kPa were determined, and the effects of different macropore structure on desorption performance were analyzed. Results show that macropore distribution of 5A-1 concentrates in 0.25-1.25 μm, while that of 5A-2 ranges from mesopore category to 0.3 μm, but 5A-3 contains both pores of 0.01-0.1 μm and 0.2-2 μm inside, reflecting a broadest distribution; 5A-3, 5A-1 and 5A-2 reach desorption equilibrium after 1100 s, 1400 s and 2000 s respectively at 0.03 kPa, indicating that abundant macropores make n-pentane fastest desorbed from 5A-3, but this advantage gradually disappears with the increasing pressure; the effective desorption diffusion coefficients of n-pentane on 5A-1, 5A-2 and 5A-3 are 4.2×10-15-2.2×10-14 m2/s, 2.0×10-15-2.3×10-14 m2/s, 7.4×10-15-2.4×10-14 m2/s respectively, suggesting that plenty macropores make the diffusivity less affected by the changes of pressure, which can guarantee a fast diffusion rate of n-pentane even at low pressure.
Decolourization of Methylene Blue by Persulfate
Authors: Hu Wei , Li Shen Xin , Wang Cheng Duan
Published: March 2013

The decolourization of dye wastewater by persulfate was studied using methylene blue as a model dye wastewater. Effects of several parameters, such as dose of oxidant, ionic strength, pH, temperature and UV irradiation, were investigated in detail. The results showed that the decolourization reaction of methylene blue by persulfate could be fitted to a pseudo-first order kinetics model. In addition, when the oxidant amount used is 2 times of methylene blue, pH 3.43 and reaction temperature for 60°C, after uv light under the irradiation of 20 min, methylene blue decolorization rate can reach more than 98%. The results are useful for the treatment of dye wastewater.
Optimization Study of Pyrolysis Process for Bamboo Waste by Orthogonal Experiment
Authors: Yang Li , Wei Yong Gang , Wang Hua , Hu Jian Hang
Published: March 2013

The pyrolysis of bamboo waste has been investigated. The effects of carbonization temperature, heating rate and carbonization time on characters of biomass carbonization was investigated by the orthogonal design. The optimized operating condition of bamboo waste was achieved by the analysis of variance: the carbonization temperature is 400 °C, the heating rate is 10 °C /min, the carbonization time is 60min.The yield of bamboo waste under the optimized operating conditions is 31.8%, and ash is 3.9%. The thermogravimetric analysis of the bamboo waste was carried out in a thermogravimetric analyzer. The analysis of TG and DSC curves indicates that the pyrolysis of bamboo waste should be divided into four steps: the dryness is below120 °C, from 120 to 240°C is preheating section, and pyrolysis occurs at 230 to 370 °C and after 370 °C is carbonization process.
Differential Expression of the Dmrt1 Gene from Ovaries of Diploid and Triploid Rainbow Trout (Oncorhynchus mykiss)
Authors: Han Ying , Wang Kun , Li Hai Long , Gao Dana X
Published: March 2013

Reverse transcription real-time quantitative polymerase chain reaction (RT-qPCR) was used to determine the differential expression of the Dmrt1 gene in ovaries of diploid and triploid rainbow trout (Oncorhynchus mykiss) 10 and 20 months post-hatch. At 10 months post-hatch there was little relative difference in the expression of the Dmrt1 gene between triploid and diploid trout. However, at 20 months the expression of the Dmrt1 gene in triploids was more than 14 times higher than in diploids. Dmrt1 expression from 10 to 20 months suggests masculinization of the ovaries, which may be virilescent in triploid females at the later development phase (20 months). This study provides molecular evidence supporting the general claims that ovaries of female triploid rainbow trout do not develop normally resulting in sterility.
Application of Ultrasonic Testing in Concrete Filled Steel Tubular Arch Bridge
Authors: Zou Zhong Quan , Wang Xu , Wang Zhi Mei
Published: March 2013

Concrete Filled Steel Tube(CFST) is widely used in civil engineering structures because of its superior mechanical performance. Yet the mechanical behavior of CFST is highly depended on the construction quality of the filled concrete. Hence it is very important for the inspection of the construction quality of the filled concrete in CFST structures. In this paper, the ultrasonic testing technique was used to detect the defect of the filled concrete of a CFST arch bridge. During the inspection, the ultrasonic transducer was moved along the circumference of the cross-section of the arch, and the defect of the concrete was comprehensively judged by detecting the change of sonic time, sonic amplitude and sonic frequency. Based on the analysis of the ultrasonic transmission path, the influences of different defects on the sonic time, sonic amplitude and sonic frequency were discussed. The detecting results were verified by core-drilling method. The verification showed that different kinds of defects defected by ultrasonic testing was in good accordance with the drilling samples, which demonstrates the adaptability of the ultrasonic detection technique in the construction quality inspection of CFST structures.
Study on Damage Location of Spatial Structures Based on Wavelet Analysis of Model Strain Energy
Authors: Li Yong Mei , Zhou Bing , Sun Guo Fu , Yang Bo Yan
Published: March 2013

The research to identify and locate the damage to the engineering structure mainly aimed at some simple structure forms before, such as beam and framework. Damage shows changes of local characteristics of the signal, while wavelet analysis can reflect local damage traits of the signal in time domain and frequency domain. For confirming the validity and applicability of structural damage identification methods, wavelet analysis is used to spatial structural damage detection. The wavelet analysis technique provides new ideas and methods of spatial steel structural damage detection. Based on the theory of wavelet singularity detection，with the injury signal of modal strain energy as structural damage index，the mixing of the modal strain energy and wavelet method to identify and locate the damage to the spatial structure is considered. The multiplicity of the bars and nodes can be taken into account, and take the destructive and nondestructive modal strain energy of Kiewitt-type reticulated shell with 40m span as an example of numerical simulation，the original damage signal and the damage signal after wavelet transformation is compared. The location of the declining stiffness identified by the maximum of wavelet coefficients，analyzed as signal by db1 wavelet，and calculate the graph relation between coefficients of the wavelets and the damage to the structure by discrete or continuous wavelet transform, and also check the accuracy degree of this method with every damage case. Finally，the conclusion is drawn that the modal strain energy and wavelet method to identify and locate the damage to the long span reticulated shell is practical, effective and accurate, that the present method as a reliable and practical way can be adopted to detect the single and several locations of damage in structures.
Internal Imperfection Detection of Concrete Composite Component Using Ultrasonic Method and Impact-Echo Method
Authors: Xiao Yun Feng , Zhang Da Hai , Liu Li
Published: March 2013

The ultrasonic method and the impact-echo method are two kinds of nondestructive test method (NDT), which are widely used, not only for concrete component, but for masonry structures. However, it is hard to detect the flaw in the concrete composite component if only with one kind of detection method. In this study, the principle of ultrasonic method and impact-echo method are outlined. And an attempt of a new method is taken, that Ultrasonic method together with Impact-echo method is used in detecting the deflection in Concrete Composite Component. It is proved that the result of this new method is more accurate and stable than that of only using ultrasonic method or impact-echo method. Introduction Introduction
Inspection of Grouting Quality for Grouted Tendon Ducts Using Ground Penetrating Radar Technique
Authors: Zhou Xian Yan , Luan Jian , Zhang Da Hai
Published: March 2013

With the wide applications of post-tensioned concrete structures, the grouting conditions of tendon ducts are paid more attentions. In order to accurately assess the internal grouting quality of the grouted tendon ducts and certainly guarantee the lifetime of prestressed concrete structures Ground Penetrating Radar (GPR), which is a kind of nondestructive testing (NDT) method, has been applied to inspect and evaluate qualitatively and quantitatively on the grouting defects, respectively. A series of in-house tests were carried out for simulating the defects of tendon ducts by foams with different sizes. The results show that the GPR technic was one of the optimal methods for inspecting the internal grouting quality of grouted tendon ducts for post-tensioned concrete structures.
FEM Analysis on Concrete Column Confined by Straps of BFRP Sheets
Authors: Wang Xiao Kun , Liu Hua Xin , Wang Xue Zhi , Zhai Cheng
Published: March 2013

More attention has been paid on the technology of BFRP in civil engineering due to it’s unique properties, such as high strength-to-weight radio, good resistance to corrosion and convenient to construction. In order to study the properties of BFRP sheets confined concrete column ,we did it through three groups of columns subjected to axial loading tests and FEM analyses, mainly considering the effect of spacing of straps of BFRP sheets confining concrete column.The results shows that the axial compressive strength and ductility of concrete column winded by BFRP straps have all increased and the process of destruction of concrete column wrapped by BFRP is longer than that of the unconfined concrete column.
Parametric Identification of Nonlinear Devices for Seismic Protection Using Soft Computing Techniques
Authors: Marano Giuseppe Carlo , Greco Rita , Quaranta Giuseppe , Fiore Alessandra , Avakian Jennifer , Cascella Davide
Published: March 2013

Passive devices for vibration control are widely adopted in earthquake engineering for mitigation of seismic effects obtaining an efficient, robust and not expensive structural protection. They are largely used in the seismic protection of industrial machines, technical equipment, buildings, bridges and others more as reliable and affordable solutions. Moreover their performances are extremely sensitive to their dynamic mechanical behavior; a reliable identification of their mechanical behavior is therefore of key importance, despite the current lack of accurate and simple standard procedures to identify parameters and models for those devices. In this work, a new procedure for the dynamic identification of passive devices is described, through standard laboratory dynamic tests and the use of evolutionary algorithms. This procedure allows to find proper mechanical law and parameters to use for an accurate structural analysis and earthquake-resistant structure design. The procedure uses standard pre-qualification and quality-control tests, and consists in the minimization of the integral measure of the difference between mathematic and experimental applied force to the device under an imposed displacement time history. Due to the amount of corruption source of the experimental data and to the deep non linear nature of the problem, the use of evolutive algorithms is the main way to solve hard numerical task in an efficient way. The proposed procedure is applicable to a wide range of mathematical expressions because of its inherent stability and low computational cost, and allows comparing different mechanical laws by ranking their agreement with experimental data. Results are obtained for different experimentally tested devices, that are viscous dampers and seismic isolators, and are reported in order to demonstrate the efficiency of the proposed strategy.
Damage Analysis of Thermal-Mechanical Coupling on Concrete Member under High Temperature
Authors: Yin Shui Ping , Tang Song Hua , Li Yong Hong , Chen Chao , Tian Fang , Luo Ying She
Published: March 2013

The fire has brought great harm to human, so it is of vital significance to establish a scientific method of structural fire resistance design to avoid personnel casualties and economic loss in the destroy or collapse of the structure in fire. The mechanical properties of materials deteriorate at the high temperature of the fire, and the structure can be damaged easily, so the damage cumulative impact must be considered in the structural resistance capability to fire. Damage mechanics is a powerful tool in the study of structural damage and destroy. In the paper, the damage mechanics is introduced into the calculation of resistance capability to fire of concrete structure, and the thermal-damage analysis of concrete member is achieved through the second development on ANSYS platform by using the residual strength thermal-damage model at high temperature.
Analysis of Moored Ship Motion under Impulsive Forces
Authors: Wei Zhuo Bin , Xiong Xian Wei , Zhang Ning , Wu Sen
Published: March 2013

To prevent the damages of the moored ship and the wharf structures in heavy weather, the ship motion and its effects on the wharf are analyzed. The moored ship motion in high winds with big waves was investigated. Firstly, the lateral wind loads and wave loads were considered as periodic impulsive forces, and the simplified dynamical model was presented. Based on the presented nonlinear impulsive differential system model, the numerical simulations and analysis were performed. The effects of recovery coefficient, damping and stiffness parameters on the system behaviors were discussed. Finally, some suggestions were made to guarantee the ship's stability or practical stability in heavy weather, and the safety of the wharf structures is thus assured.
A Computerized Method for Dynamic Response of Vehicle-Bridge Interaction System under Various Conditions
Authors: Xiao Yao , Chen Zheng Qing , Hua Xu Gang
Published: March 2013

A computerized method is presented for computing the dynamic responses of bridges under moving vehicles. The bridge and vehicle are treated as integrated system and modal superposition method is applied to transfer the equation of motion into modal coordinate system. The road roughness/unevenness is also considered. The effects of different vehicle models, vehicle passing speed and road surface roughness on bridge dynamic responses are studied. The impact factor representing the dynamic effect of passing vehicle is calculated for different road surface roughness
Probe of Low Carbon Construction Technology and its Application Feasibility for Buildings
Authors: Shen Liang Feng , Song Tian Ping , Tang Yan Qun
Published: March 2013

From the discussion of the importance of the low carbon construction technology in China, the low carbon construction techniques are summarized in this paper, and especially the main low carbon construction techniques have been analyzed theoretically, then its application foundation and feasibility have been made clear. Through the case analysis, the actual effects of the low carbon construction technology have been grasped, so the related to issues of development optimization have been put forward, in the end can provide the reliable basis of promotion for low carbon construction techniques.
Multi-Objective Dynamic Decision of CIA for Cascade Hydropower Development
Authors: Zhong Shan Shan , Zhang Fei Lian , Wang Hua Long
Published: March 2013

Considering the characteristics of hydropower cascade development project’s cumulative environment impacts, such as scope broad, many indexes and so on, a new evaluation method- dynamic multi-objective decision method is adopted. This method makes alternative ranking under three-dimensional coordinate, then assessing the cumulative environment impact and its developing trends. The result indicates that this method can not only observes the cumulative impact’s changing degree in the past time, but also predict the changing trends in future time. It is able to comprehensively evaluate the cumulative environment impact.
Application and Analysis of GMT Plastic Template in Engineering
Authors: Zhao Jun , Yao Yin Wei , Tang Zhong Ping , Tian Feng
Published: March 2013

According to a construction case of residential buildings in Ningbo, this paper describes the technology performance, construction technology and innovation of the GMT template. Comparison with other common template, it has proved that this new building template has the advantages of smooth surface, easy remolding, light weight, good corrosion resistance, formwork turnover frequency and recyclable. So it has a good application value.
Prefabricated Buildings Selective Disassembly Strategy
Authors: Zhong Ji Xiang
Published: March 2013

The assembly building is sought after by people For its speed, subject to the constraints of climate conditions, seismic energy saving and environmental protection, construction of low cost, flexible and diverse housing. However, in the assembly building maintenance, scrap processing and recycling of how to improve the efficiency of demolition is a new issue to be resolved. In this paper, based on the components of the demolition wave optional disassembly planning algorithm, by the definition of prefabricated building demolition wave is a topological relationship of certain components in the assembly building to reflect the components of the demolition order. The calculation of the algorithm is small, easy to use it to carry out efficient search, optional optimal component disassembly sequence, and thus improve the efficiency of disassembly.
Study on the Quality Management of Construction Enterprise
Authors: Ren Sen Zhi , He Guo Jing
Published: March 2013

Quality management was the key to the survival and development of construction enterprises. This paper discussed the construction enterprises should carry on the quality management at two levels of the internal quality management of construction enterprises and their construction project quality management, that could make construction enterprises to embark on a high-quality and efficient development road.
Study on Short-Term Rigidity of Precast Composite Slab with Steel Truss and Concrete
Authors: Cheng Jie Yun , Zhao Lei , Yang Jian Jun
Published: March 2013

Composite slab by steel bar truss and concrete was a new style of floor slab. Because there were the small steel bar trusses in precast member, its short-term rigidity was higher than the normal composite floor slab. The structure was divide into four kinds, according to the relative location of the neutron-axis and the combined interface of slab; the relative value of the moment in first phase and the cracking moment of the precast slab. The different formulas to calculate short-term rigidity of precast member for four kinds were obtained. Through the models of composite slab by steel bar truss and concrete with different dimensions were established using finite element structural program, the formula feasibility was confirmed
Experimental Research on Crack Width of Retard-Bonded Partially Prestressed Concrete Beams
Authors: Feng Xin , Zhou Xian Yan
Published: March 2013

Retard-bonded prestressed concrete which has appeared in recent twenty years is a new and distinctive prestressed system. For the research on mechanical behavior and service property of retard-bonded prestressed concrete members, retard-bonded prestressed strands were made by manual work in this paper. Experimental research and theoretical analysis of three retard-bonded partially prestressed concrete T-beams were carried out under static loadings. The law of crack development and distribution both with the relationship between load and maximum crack width were studied in the paper. Test results were contrasted with experimental studies of two traditional partially prestressed concrete T-beams, and the characters and merits of retard-bonded partially prestressed concrete T-beams were obtained. It provides theoretical reference for the actual project application of the new retard-bonded prestressed concrete system.
Analytical Investigation on Concrete Filled Double-Skinned Steel Tubular Column Composite Frame with Bolted End-Plate Connections
Authors: He Wen Hui , Yang Chun Qiang , Yi Yuan Ye , Tang Zhi Han , He Peng Chen , Weng Hai Bing
Published: March 2013

Simulation studies of seismic behaviour of bolt-endplate connected composite structural systems consisting of CFDST columns and steel beams frame with reinforced concrete slabs are presented in this paper. Based on fiber-section model, analytical models were developed to predict the elastic-to-plastic behaviour of the prototype frame. Analysis results indicated that the structural behaviour under the simulated seismic loadings was consistent with the expected performance objects for different earthquake hazard levels corresponding to current seismic design codes, implying that effective seismic performance of composite CFDST frame with bolted connections can be achieved. The primary analytical simulation shows the suggested bolted endplate CFDST system has the potential to offer appropriate strength and adequate stiffness for buildings located in areas of high earthquake intensity, and provides basic information for further experimental researches to validate the seismic performances of the bolted end-plate CFDST structures.
The Experimental Study on Creep and Shrinkage of High Strength Concrete with Fly Ash
Authors: Wang Jian Qun , Fang Zhi , Tang Zhi Jian
Published: March 2013

Shrinkage and creep characteristics of concrete are significant factors in the design of prestressed concrete structures. With large scale/span concrete structures developed, the fly ash or other blends are added into high strength concrete to improve the mechanical properties and workability. As a result, the existing shrinkage and creep predicting models have certain limitations. The creep and shrinkage behavior of high strength concrete with fly ash are studied in this paper. Proper predicting model for shrinkage and creep of high strength concrete is recommended. The influence factor of fly ash is proposed as well. These conclusions would be of great useful for structures with fly ash concrete.
Experimental Investigation of Wind Loads on Fish-Shaped Roof Structures
Authors: Zhang Ming Liang , Li Qiu Sheng
Published: March 2013

Wind tunnel tests of 1:100 rigid model of fish-shaped roof structures were carried out. The mean, fluctuating (RMS) and peak pressure coefficients, the local shape coefficient distributions on fish-shaped roofs were presented and discussed. It was found that negative pressures (suctions) occurred on the most areas on the roofs, and high negative pressure coefficients occurred on the eaves and cantilevered roof parts. When wind flows blew along the corridors under the roofs, the flows enhanced suctions on the surfaces of the roofs, and the suctions on the lower surface were greater than those on the upper surfaces, positive pressures occurred on that area after superposition of wind actions on the two sides. The roof eaves and regions above the corridors experienced the worst RMS pressure coefficients and the worst minimum pressure coefficients. The distribution characteristics of the worst RMS and minimum pressure coefficients were found to be quite similar to those of the mean pressure coefficients. The results obtained from the experimental investigation are expected to be useful in the wind-resistant design of complex roof structures in typhoon-prone regions.
Effect of Turbulence on the Aerodynamic Stability of Long Span Bridges
Authors: Li Chun Guang , Chen Zheng Qing , Zhang Zhi Tian
Published: March 2013

The study deals with the problem of turbulence effect on the instability of a long span suspended bridge. Wind tunnel test of three representative section models have been carried out in four type of passive grid turbulence flow to clarify the effect of turbulence intensity and turbulence scales. It was found that the turbulence has little effect on the derivatives of those streamlined deck sections, while it exhibits significant stabilizing effect on the bluff rectangular section prism. The loss of spanwise correlation may not be the main reasons induce the change of flutter stability in turbulence.
Unascertained Average Clustering Analysis on SMA Mixture Ratio Design
Authors: Wen Chang Ping , Zhao Liang
Published: March 2013

Based on unascertained mathematical theory, the unascertained average clustering model (UACM) is established in the ratio design of stone matrix asphalt (SMA). Six parameters including Marshall stability, flow value, volume of air voids (VV), void in the mineral mixture (VMA), VCAmix, and asphalt saturation are selected as the index in the clustering analysis to establish UACM of design indexes including penetration, ductility, softening point, percent passing 9.5 mm sieve, percent passing 4.75 mm sieve, percent passing 0.075 mm sieve, and the asphalt-aggregate ratio respectively. The study shows that UACM has strong applicability; the results meet the engineering requirements, and can be provided a new way of SMA mixture ratio design in practical engineering.
Study on Identification and Classification of Expansive Soil Based on Bayes Discriminant Analysis Method
Authors: Qiu Yan Jun , Wen Chang Ping
Published: March 2013

Based on the principle of Bayes discriminant analysis, Bayes discriminant model (BDM) for evaluation of expansive soil in sub-grades is established. Four indexes including free expansive ratio, liquid limit, plasticity index and moisture content of standard absorption are selected as the factors for synthetic evaluation of expansive soil. The grade of shrink and expansion is divided into four grades that are regarded as four normal populations in Bayes discriminant analysis. Bayes discriminant functions obtained through training a set of expansive soil samples are employed to compute the Bayes function values of the evaluating samples, and the maximal function value is used to judge which population the evaluating sample belongs to. The optimality of the proposed model is verified by back-substitution method. The study shows that the prediction accuracy of the proposed model is 100% and could be used in practical engineering.
Numerical Analysis of Anchor Reinforced Length Effect on Highway Slope
Authors: Zou Jing Rong
Published: March 2013

Based on the strength reduction method，the anchor reinforced slope has been simulated by elastic-plastic FEM. The safety factor of reinforced slope with anchor was gotten by heuristic search method. The plastic zone running through or not is taken as a standard to solve slope safety factor. The research results show better the distribution situation of stress and strain in slope. It proposes a new method to evaluate the stability of slope with complex boundary conditions. Taking a slope engineering for example, the stability safety coefficients of the slope are calculated when the slope is reinforced with anchors of different length. When the design length of anchor is longer than a certain value, the anchor length has little effect on improving the stability of slope and slope toe. Consequently, the reasonable design length of anchor is put forward