2013 volumne 34 Issue 01
ZENG Li1,ZHU Yun-dong1,ZHAO Zhuo1
Abstract: Through test on mechanical and durability index of concrete with supplementary cementitious mate-rials,the correlation of chloride diffusion coefficients at dfferent ages with cement amount per cube meter, ce-mentitious materials amount per square meter,cube crushing strength,carbonation depth and dynamic elasticmodulus are studied. The test results show that 84d chloride diffusion coefficient has a good linear correlationwith cementitious materials amount per square meter. Chloride diffusion coefficients at different ages all re-duced with the increase of cube crushing strength,and chloride diffusion coefficients at different ages all havea good linear correlation with 84d cube crushing strength. Chloride diffusion coefficients at different ages allincreased with the increase of carbonation depth,and 84d chloride dffusion coefficient has a good linear corre-lation with carbonation depth. Chloride diffusion coefficients at different ages all reduced with the increase of84d dynamic elastic modulus.
BAO Jun-an,YANG Ping,WANG Xu-nuo
Abstract: In order to reveal the law that the cement-improved soil controls frost heave,experimental researcbon frost heave properties were conducted with two typical soils in Nanjing region ,clay and sand,mixed withthe cement. The experiments show that: frost heave coefficient of clay or sand cement-improved soil declinesexponentially with mixing ratio of cement increasing,enhances linearly with moisture content increasing,de-clines exponentially with instar increasing,enhances linearly with the cold junetion temperature increasing, declines exponentially with load increasing besides there is an optimal mixing ratio,while it is the optimal mix-ing ratio,frost heave coefficient of cement-improved soil are lower,the optimal mixing ratio of clay and sandin Nanjing region is 10% and 5% . By comprehensive analysis,when using the freezing method,before freez-ing, a certain amount of cement can be mixed into the clay or sand, and it is necessary to place it for a periodof time,which can reduce frost heave and thaw subsidence,thus reducing the harm to engineering and the en-vironment.
LI Li1,WANG Zong-hua,1LI Tian2,ZHENG Wei-hua1
Abstract: Standardized design of isolated structure is given based on the kind of rural residential house appea-ring most in Zhongyuan area,and shock-isolation design method in practical application is sought. The stand-ardized design tables are formed , and the shock-isolation effect is contrasted,the analysis suggests that: for thevillage residential building structure which is less than six layers,with the house layer or the total length of theresidential flat increases,isolation effect is increased gradually,but the development is slowing down.
YAN Xi-kang1,2MA Kang1,YAN Hua2,CHEN Qian-qian1,CHEN Pei1
Abstract: The seismic behaviors such as failure pattern,hysteretic characteristics,keleton curve,displace-ment ductility,rigidity degradation,energy dissipation and residual deformation of two-story two-bay reinforcedconcrete frame with construction joint are studied systematically.The results show that carefully treated con-struction joint has a greater impact on seismic performance than crack and integrity of reinforced concreteframe.
ZHENG Chen,ZHENG Chang-jiang
Abstract: Public transportation guidance system is an important part of public transportation information system. lt is an important means to improve the quality of bus service and reduce the waste of public resources,in which bus speed induction is particularly important. In order to reduce the bus driving delay,this paper u-ses speed induction to control bus arrival time at the intersection. It uses red time to finish passengers’ up andoff when there is a station at the intersection. When there is no station,bus will leave the intersection beforethe end of the green time. And through the simulation example,we find that bus travel time significantly re-duced after optimization. The method can be used for a variety of city roads with bus lanes. Ilt is simple andeffective,and it has some applicability.
GA0 Pan-ke1,2,XIE Yong-li1
Abstract: Based on the realization of the defects in the general BP( error back propagation algorithm ) artificialneural network( ANN ) , an approach based on improved BP ANN for displacement back analysis of soft andweak rocks for tunnels is proposed in this paper. This BP ANN was improved in two ways , neural structure andalgorithm, by using increased feedback in output of neural cell , dichotomy theory to chose neurals’number ofhidden layer , improved inertia revise,algorithm,varying step-size algorithm ,improved error function.The in-tegrated error between monitor number and simulation number was controled with in 4% . Aiming at the exactand dependable parameters for construction of tunnels with soft and weak rocks,BP ANN was combined withFEM (finite element modeling ) numerical simulation successfully.
ZHOU Shu-fen1,HAO Xian-wu1,LI Zi-qing1,KUANC Hong-qiao2
Abstract: In view of the mechanical characteristics of side pier in long span and low pier continuous rigidframe bridge,combined with the advantages of concrete flled steel tubular structure,we propose for the firsttime as pier of such rigid frame bridge,and carry out the corresponding research.Taking Weihe it bridge asan example which is an eight span continuous rigid frame bridge,by the finite element software Midas eivil,we comparatively analyzed the steel tube concrete piers and reinforced concrete piers in adapting to the upperstructural deformation,the internal force distribution,the amount of material. The results show that comparedwith the reinforced concrete piers under the same conditions,the steel tube concrete piers have smaller anti-push rigidity,better ability to adapt to the upper structural deformation,more balanced structure force,lessmaterial consumption,and lower project cost. By comparing the maximum horizontal displacement at pier topof two kinds of pier with different heights,we pointed out the reasonable application scope of the steel tubeconcrete piers.
ZHANG Hong-mei1,BIAN Kai-lei2,LIU Sheng-jie3,XU Dong3
Abstract: In order to forecast the time regularity of the asphalt thermal and oxygen aging,the RTFOT experi-ment was applied,according to the principle of evaluating system stability with the variable tendency of itscompatibility,the destabilization of asphalt aging was predicted with the grey-cusp-catastrophic destabilizationprediction model. The research results show that the catastrophe exits in the aging process, and hysteresis phe-nomenon exits between catastrophe and aging actions. For the asphalt mixture,the heating time should not ex-ceed 50 min, and to make the asphalt pavement have the long services life,the measures should be taken toextend the catastrophic happened time.
LIU Zhi-bin,FANG Wei,CHEN Zhi-long
Abstract: To study the quantitative characterization methods of moisture infiltration in loess,column leachingtests with dye tracer solution were conducted.The variation of electrical resistivity of loess during moisture in-filtration and the morphology of cross - sectional stained area of different depthes after infiltration were quanti-tatively analyzed.The test results indicate that under the same condition of moisture infiltration,the electricalresistivity decrease of natural loess with time is higher than that of remolded loess,while the electrical resistivi-ty decrease of remolded loess possesses staged property.Due to the existence of macropores,the moisture caninfiltrate into natural loess deeper than remolded loess,and the stained area ratio decreases less in natural lo-ess than in remolded loess.Generally the fractal dimension of stained area boundary increases monotonously inremolded loess,but increases first and then decreases in natural loess.
HUANG Qiang,GAO Ying-yu,NIU Bo-lin, BAN Chun-lan ,ZHANC Rui
Abstract: The solubility of R-a-phenylethylamine-D-tartrate and S-α-phenylethylamine-D-tartrate in metha-nol,ethanol,DMF and a solvent mixture of acetone and water with the volume ratio of 5: 2 were measured bydynamic method under atmospheric pressure. The solubility of the two salts in the above mentioned solventsystems increase with increasing temperature. The experimental data were correlated with simplified equation,Apelblat equation and the polynomial equation,the ranges of average absolute relative derivation ( AARD)were 0.66
LIU Li-ping,SHEN Li-ying,CHANG Chun
Abstract: Several processes of saccharification based on steam-exploded corn stalk were compared in this pa-per,and the best process of saccharification is ; adding 1/3 cellulase firstly,adding 1/3 cellulase after 24 h,then adding the rest of the cellulase after 12 h,and saccharification 48 h in all.On this basis,the better con-ditions of fermentative process were investigated by single-factor experiment and orthogonal test. Under the op-timum conditions,the concentration of butanol can reach 9.42 g/L.
LIU Pu,LI Ke-rang,ZHANG Shuai
Abstract: Chitosan Schiff base derivatives were synthesized by the condensation reaction of chitosan andsalicylaldehyde in an ionic liquid,1-butyl-3-methylimidazolium chloride ( BmimCl). The effect of some reac-tion conditions,such as the molar ratio of free amino group to salicylaldehyde,reaction temperature and reac-tion time on the degree of substitution ( DS) has been investigated.The DS could be reached 29.2% at theoptional condition(0.15 g chitosan dissolved in 10 g BmimCl,the molar ratio of free amine group to salicylal-dehyde of 1:2.5,a reaction temperature of 80 ℃,and reaction time of 2 h). The product was characterizedby Fourier transform infrared ( FTIR ) ,nuclear magnetic resonance ( NMR),and X-ray diffraction (XRD), respectively. A series of chitosan schiff base derivatives was synthesized under the optimal conditions.
WANG Su-lan1,YU Jie1,HU Meng2,XING Chuan-hong1
Abstract: In order to investigate the effect of the MBR process in phosphorus and nitrogen removal for munici-pal wastewater,A3/O- MBR is used on the mixed municipal wastewater to do the pilot study in the test. Theresults show that,when the system is working under the normal condition,the average removal rates of TN、TP ,COD 、NH3-N are 74.59% ,95.10% ,93.04% ,93.70% ,respectively,and the average concentrations ofTN, TP ,cOD, NH,-N are 9. 51 mg· L-1,0.28 mg· L-1,28.24 mg· L-1,1.69 mg·L-1, respectively.which achieves good effect in phosphorus and nitrogen removal.
ZHAO Hong-liang1,ZHANG Chuan1,WENG Kang-rong1,XU Zhong-xin1,JIN Chen-yue3
Abstract: To improve the service performance of magnesium alloy crankcase used in the electric hammer,theeffect of RE on the microstructures and properties of AM60B alloy is studied ,and the optimum content of REin AM60B alloy under the gravity casting condition is obtained. Then the RE is added into the AM60B alloyunder the industrial die casting condition,and the effect of RE on the microstructures and properties of die -castings is studied. The results show that the optimum content of RE is 1.0% under the condition of gravitycasting. When 1% RE is added into the AM60B magnesium alloy crankcase,the microstructures are refinedand the average grain size decreases from 39um to20pum. The brinell hardness,impact toughness and benchendurance property of the crankcase are all improved.
SHAN Li-hong1,2QIAO Xing1,2,Ll Yang1,2,ZHANG Lu-jia1,2,JIA0 Kai1,2,LIU Hong-min1,2
Abstract: Dihydroepiandrosterone (DHEA ) is one important bioactivity compound and one important interme-diate of steroid drugs. It is for the first time to report the biotransformation of DHEA by Mucor circinelloidesand two products was obtained. Furthermore,the 16-benzylidene derivatives were synthesized by Claison -Schimidt reaction. The cytotoxic evaluation showed that these derivatives had better activity than the parentcompound.
XU Min1,LIU Xiao-hui1,WANG Xi2,XU Hui3,WANG Yi3,CAO Yuan-qian4
Abstract: In order to improve the accuracy of calculation of the power system frequency,a high-precision fre-quency measurement method based on the 4-term Nuttall windowed recursive DFT interpolation algorithm hasbeen put forward. Energy of four cosine window is more concentrated in the main lobe,very small in the sidelobe,so the 4-term Nuttall windowed recursive FFT interpolation algorithm can greatly reduce the effects ofspectral leakage,and spectral interference is very small, which can reduce the frequency measurement inter-ference caused by spectrum leakage and harmonic,and the frequency offset formula of the method is simple.In order to reduce the amount of plus four cosine windowed FFT calculation,this paper. introduces the plusfour cosine window recursive DFT method which improves the traditional method,these improvements effec-tively reduce the 4-term Nuttall windowed recursive DFT interpolation algorithm and improves the calculationaccuracy of the frequency.Simulation results verify the calculation accuracy of the proposed algorithm.
XU Ying-hui,YAN Zhi,LUO Ying-hong
Abstract: The signal cable was interfered by the lightning current mainly via the space inductive coupling andthe earth resistive coupling when we analyzed the way that lightning current acted on the signal cable.Accord-ing to the catenaries model of the route,electromagnetic transient software ATP-Draw was used to establishlightning catenaries insulator flashover lightning current propagation simulation circuit. Studies have shownthat : Cable sheath current coupling led to over voltage and the earth resistive coupling caused the potentialrise, and both factors have the biggest influence on signal cable. While contact line,protection line andthrough ground line current coupled to the cable core voltage is small,signal cable core over voltage along withthe increase of grounding resistance increases. By reducing the signal cable grounding resistance,separate setof earth electrode and other measures to improve the lightning interference on the signal cable. References tocatenary lightning strengthen the implementation program of Beijing-Shanghai high-speed railway; this paperalso analyzes the height of ground wire erected,and gives advice erection height to improve the catenary light-ning withstand level.
YUAN Feng1,DING Ze-xin1,Ll Yue-mei2,ZHU Jun1
Abstract: Based on substance-field analysis theory,firstly,the design conflicts are described,according tothe actual demands of design for the layout of Spin Riveting Machine in the automatic assembly system of sawchain.Secondly ,substance-field model of chain shaft riveting is set up.Finally,the design space conflicts aresolved by using the 76 standard solutions and the final ideal solution of the layout of Spin Riveting Machine isfound out,which reduces the whole system ’s research and development time. In a word,the successful trialof automatic assembly system of saw chain will greatly enhance saw chain ’s assembly efficiency and quality ,reducing its production cost and prolonging its using life effectively,so it is important to the technology pro-gress of enterprises.
YUAN Feng1,DING Ze-xin1,Ll Yue-mei1,2,ZHU Jun1
Abstract: Based on substance-field analysis theory,firstly,the design conflicts are described,according tothe actual demands of design for the layout of Spin Riveting Machine in the automatic assembly system of sawchain.Secondly,substance-field model of chain shaft riveting is set up.Finally,the design space conflicts aresolved by using the 76 standard solutions and the final ideal solution of the layout of Spin Riveting Machine isfound out,which reduces the whole system ’s research and development time. In a word,the successful trialof automatic assembly system of saw chain will greatly enhance saw chain ’s assembly efficiency and quality ,reducing its production cost and prolonging its using life effectively,so it is important to the technology pro-gress of enterprises.
XIA Yi-min,HE Li,XIE Jing-hua,YU Hong-yun,ZHU Xiang-heng
Abstract: This paper studies the hydraulic thrust system of Herrenknecht shield machine,establishes themathematical model of pressure fluctuations of pipeline and analyses the pipeline effect on the shield thrust eyl-inder displacement.Modelling and simulation of the hydraulic system based on the AMESim software. It alsodiscusses the influence of pipeline effect on the shield hydraulic thrust system are made and pipeline structureparameters on the dynamic performance of shield thrust cylinder displacement. The results show that the pipelength and diameter ane key factors influenciny the trust eylinder displacement and shield correction distance,what ’s more,the longer the pipeline length and the smaller the pipe diameter,the pipeline effect is more obvi-ous on the trust cylinder displacement
HUI Yan-bo,WANG Hong-xiao,FENG Lan-fang,XIA Zhao-yi ,WANG Qiao,XING Zhi-wei
Abstract: Based upon the fatigue crack problems of a light-bus hybrid vehicle frame after run 5 ,000 km,a fa-tigue crack simulation is done for this with the comprehensive application of multi-body dynamics,finite ele-ment analysis and fatigue analysis.A multi-body model is set up in MSC.Adams/Car with load spectra of B-grade road acquired,a static analysis is conducted by using inertia relief technique in MSC. Nastran,a fatiguelife analysis is performed in MSC.Fatigue, the main reasons that lead to fatigue breach is analyzed to find out.One measure is proposed to pick out according to demand. In the end,the verification of the modified modeland the comparison of the fatigue life between the prior and the modified project was done.
ZHANG Ai-mei1,wU Wei-wei1,LI Lin-yan1,ZHANG Hong1
Abstract: Aimed at the feature that the parts of dry-type transformers are serialized and the drawings from 3Dparts are not in conformity with national standard in Inventor,this paper did secondary development work ofInventor to develop a system which uses the tool of VB, database Excel as data source. This system can gener-ate drawings automatically from serialized 3D parts in Inventor.
LIU Guang-rui1,HUANG Zhen1,HAN Li-li2,BI Jing-kai1
Abstract: The control of the visual-servo robot is feedback controlled through presenting the feature space ofrobot system by the graphic Jacobimatrix of the systerm.A SCARA robot system is established firstly. In viewof the physical meaning of the system Jacobianmatrix, the system state equation would be built according to theincremental of Jacobionmatrix,then the Jacabian matrix would be estimated on-line through the Kalman filte-ring. This method is analyzed based on the MATLAB simulation and applied to the tracking of the two dimen-sional target, and the validity of this method was tested finally.
FENG Lan-fang1,XIA Zhao-yi1,HE Qiang1,WANG Hong-xiao1,HUI Yan-bo1,XING Zhi-wei1
Abstract: The finite element analysis model for the minibus is set up by HyperMesh software based on theCAD model.In the LS-DYNA environment,the vehicle frontal crash nonlinear simulation is done,and crashrelated parameters are obtaind. The main energy-absorbing in crash process are analyzed. Simulations are car-ried out and the results coincide well with those of real minibus crash test.The simulation and vehicle crash re-sults show that : by using the finite element analysis for vehicle frontal crash simulation is effective.
KANG Ji-wei
Abstract: The parameters of microtopography and micro-climate are of great significance for the constructionand safety of the power grid. This paper sets forth the characteristic and cause of formation icing,analyzes thecharacteristic of accidents concerning covering ice on the lines in the microtopography and microclimate Dis-trict,and gives the measure that prevents and cures the similar disaster accident of formation icing replays,The research results will provide the reference for the transmission line covers ice taking precautions againstaccident to distant span of our country high voltage grade for the stability of the electric system.
ZHANG Xin-rong1,LI Yuan-cai1,LI Bao-yun2
Abstract: In order to control the traveling speed of the paver experimental bench accurately,according to thespecific function requirement of the mobile road slab of the experimental bench,the design of the hydraulicsystem and control system of the mobile road slab is accomplished by means of adopting electro-hydraulic con-trol technology and using PLC. The pump-control-motor control method is introduced.The motor speed varieswith the pump discharge when the duty ratio of the PWM signal controlled by the controller changes. Thespeed of the mobile road slab changes according to a slope function,which avoids the impact when the mobileroad slab starts to move or its speed is sharply changed. The constant - speed control of the mobile road slab isaccomplished by adopting PID algorithm.
WANG Zhi-yang1,YANG Ji-long2
Abstract: This paper firstly analyzes and simulates the relational performance of the conventional noncoherentsynchronization system. According to the bad impact on acquisition performance by the effect of residual codephase offset,it proves that the sum of the two successive matched filter outputs can conquer the effect if 1/ isintegral. Based on the scheme and conventional design,it puts forward a new algorithm of noncoherent syn-chronization spread spectrum acquisition. Many results and simulations are also given to show that the pro-posed algorithm has better performance than the conventional design.
YANG Shou-yi,BAI Wen-juan,FU Ya-nan
Abstract: In a practical circumstance,because the reliability of each cognitive user’s local sensing result isdifferent, the detection performance cannot be improved with the increase of the number of participating users.In consideration of the necessity of cooperation and collaboration gain, a new scheme-partner selection in coop-erative spectrum sensing based on SNR comparison is proposed. Theoretic analysis and computer simulationshow that the proposed scheme improves the detection performance and reduces the number of cognitive userswhich participate cooperative spectrum sensing at the same time,so this new scheme can improve the efficien-cy of cooperation.
LIU Zhi-huai1,2
Abstract: Sharp lateral variation of weathering-layer velocity and thickness in complex terrain area can causeserious statics problem. To solve the statics problem of this kind, a method which uses the micro-logging infor-mation to build near-surface model along the variation tendency of subsurface structure is introduced. Thenear-surface model which has been built by the method is inputt as the prior-information of tomography inver-sion method to improve the accuracy of inversion result.The rusults show that the method is available in realexample of seismic data processing.
ZHANG Wei-dang,LI Ping
Abstract: How to improve the channel coding capacity and reduce the bit error rate has been the main re-search directions of channel coding. In order to improve the BER performance,based on a formula derivedfrom the union bound which can estimate the bit error rate for every position in the codeword sequence, a theo-retic method to optimize the bit energy is presented and applied to several kinds of channel codes. The analysisand simulation results show that the method can reduce the average BER noticeably,especially at higherSNRs.
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