2013 volumne 34卷 Issue 03
SHILi,LI Xiao·liang,WANG Zhi-zhong
Abstract: In this paper,a method waspresented to determine the bandof gamma oscillation,and the eharac— teristics of the gamma oscillation response to simple graphics with different topologies wasexplored.First,the method combining wavelets transform and power spectrum wasadoptedto determine the accurategamma band range of the localfield potentials in rat’S primary visual cortex.Secondly,the latencyperiods ofgamma oscillation for simple graphics stimuluswith different topologies were calculated andthe curves of mutual informa.tionbetween the stimulus sequences andpower spectrums in gamma bandwere estimated.The means,maxi.mumvalues and the frequencies at themaximumvalues ofthe curveswereextractedas the feature parameters.Finally,these characteristics were analysed statistically with one—way analysis of variance.The experiment re.suits showthatundervisual stimulations the gamma-bandoscillations exist obviously in the primary visual cot.tex(V1)ofanesthetized rat.The gamma oscillations were significantly selective to the topological features of simple graphic stimulations.
LIAOXiao-hui,LIANGHeng—na,DING Qian
Abstract: Withwide application ofpower cable in transmission anddistribution systems,the demandforcable fault location accuracy is improved.In orderto locate cable fault accurately,thewavelet transform is appliedin detectingthe travelingwave signal of power cable.According to the principle of singularity detection of signals,the travelingwave starting pulse andreflection pulse time point is determined bysearchingmodulusmax— imum,andthen locatingbysingle terminal travelingwavemethodforthe online fault location.The experimental results show that the traveling wave singularity point can be detected by using localized time——frequency characteristic of wavelet transform,thereby the accurate time of pulse arrival is obtained.This method is not affected by fault type andthe range error is small,which can achieve ahigher fault location accuracy.
YANG Li-xi1,CAI Hong-fei1,REN Jia-yin2, SUN Heng2 , GUO Chen-guang1
Abstract: In order to make the evaluation index weight more reasonable,and achieve the reasonable predic-tion of the remaining life of the power transformers, this paper used three - scale method to construct judgmentmatrix , and combined the line normalization method with eigenvector method to achieve the improvement of thefuzzy analytic hierarchy process.This method is applied to the transformer remaining life assessment model,has improved the objectivity and rationality of the judgment matrix,and enriches the basis for this assessment,the results of the assessment are more accurate and have the practical guiding significance.
FENC Dong-qing,PAN Lei
Abstract: In order to enhance performances of energy saving and comfort of a lighting system , some intelligentcontrol strategies are discussed to get the best combination of natural light and lighting fixtures as to indoorlighting. Based on the solar altitude angle and the window azimuth,the solar altitude angle of the position ofthe human eye can be calculated , and the eurtain adjustment model is built here , thus the requirements of eyescomfort will be met by adjusting the position of the electric curtain. When the natural light is insufficient,it isneeded to open the lamp to fill light. The best combination of lighting fixtures luminance is solved out by useof the improved particle swarm optimization,hence realizing the comprehensive optimum of comfort and ener-gy-saving. Finally,the effectiveness of strategies of control is verified by the simulation of actual offices mod-el.
BAO Yi’ , HU Jing , GUO Han’,CHEN Gen-yong’
Abstract: In view of the impact of metro traction power load on the urban network , according to the pre-designdata and the short 、 mid and long-term metro transit scale of Zhengzhou metro transit line 1 and 2, this paperused the average volume method to obtain the transit supply power by specifically quantum calculation , and theload forecast can be got with linear regression method. Finally,the evaluation of the impacts of Zhengzhoumetro traction power supply system to urban distribution network can be achieved. The analysis showed thatthe contribution rate of rail transport electricity to the distribution network is about 2% , and the rail transitpeak load with urban network peak load does not overlap, so the impact of Zhengzhou rail transit system elec-tricity grid is very small. Its conclusions can provide a reference for the network planning in Zhengzhou.
ZHANG Jian-hua1, YU Hui1,HEI Ling-qiao2,WANG Ming-xia1,WEl Ying-jun3
Abstract: This paper introduces a novel control design of gamma knife positioning bed.Respiratory move-ments would inevitably cause tumor displacement. In this design,tumor displacement model produced by hu-man respiration was established through BFCS algorithm. Firstly , piezo sensor was used to collct respiratorysignal.Secondly, in order to make the positioning bed move by reverse respiration,after receiving the respira-tory signal,single chip microcomputer ( SCM) system would control stepping motor. The simulation experi-ment results showed that this design can reduce the influence of respiratory movements on the precision of ra-diotherapy,which produces a novel method and theoretical basis for the control of gamma knifepositioning bed.
FAN Chun—zhen,WANGJun—qiao,CHENG Yong—guang,LIANG Er—jun
Abstract: We investigate the electric fielddistribution around ferromagneticnanoparticles(NPs)inferrofluids underthe infuenceof external magneticfield.Specifically,magneticcore(cobalt)coated with a metallic lay.er(gold)isconsidered,which incorporated optically actively component with magneticNPs.Due to the magnetic response,the core/shellNPswill alignalong the direction of external magnetic field,thus forminga linear NPschain in the system.With the solution of Laplace’S equations,electric fields inside andoutside the NPschain are explored as a function of the incident wavelength operatingonthe basis of mutualinteraction a— mongthe polarizedparticles.Analytical study showsthat themaximummagnitudeof the electric filed is closely related to the resonant incident wavelength.the metallic shell thicknessandthe inter.particle distance.
ZHOUCai—rong,WANG Xiao—song,WANG Hai—feng
Abstract: Taking the extraction rate as the indexes,the optimal extraction processing conditionswereexplored by the single—factor experimentand the uniform design experiment.The kernel of cornus officnalis wastreated 6minunder the condition ofmicrowave radiation before extraction process wasdone by acetone as the extrac.tion solvent.The optimum conditions werefound to be water—bath temperature of 70.5℃.extracting time of 75min andliquid—solid ratio of 12 mL/g.Thecomponentsextractedweremainly linoleic acid,oleicacid,pal.mitic acid,etc.byGC—MS.The results provide reference for exploiting and utilizting active ingredients for the kernel ofcomus omcnalis.
LI Hui.ping1,JIN Su-jing1,LI Xue—ping2,PANGHa01,YANG Jin.jil,ZHANGJun3
Abstract: Aluminaredmud has not been utilized effectively due to its highemission andstrong alkaline.In— dustrial flue gas whichhas high S02 should be desulfurized to meet up to the standards.The mineral component,chemicalcomposition,grain sizeandmicrostructure ofalumina redmud from Henan BranchofChinaAluminum Co.were determined in this article.The orthogonal experiments and single factor experiments have been done in the self—designed 1700×60mmglass absorption device which accessories were installed in the laboratory.The influential factors such as liquid-solid ratio,flue gasflow,and liquid—gas ratio were examined throughthe orthogonal tests.The optimal conditions:liquid—solid ratio is 7:1(kg/kg),fluegas flow is 3.6 m’/h liquid-gas ratio and 12 L/m3.Under these conditions.the maximum efficiency ofFGD is more than 95%.At the sametime,compared with the currentlimestone—gypsum wetmethod,underthe same conditions redmudhas a better absorption effects.
ZHAN Yu.zhong1,LI Xiao.xul,WANGFa2,CHENYi.1iang1
Abstract: Zeolite L was synthesized by using silica aerogel and potassium aluminate as raw materials and shortcarbon chain saturated alcohols as additives. The effects of methanol,ethanol,isopropanol,butanol,glycoland glycerol on the erystal size and crystal morphology of zeolite L were investigated systematically.Particlesize of zeolite L synthesized without adding additives was small and crystal morphology was flat eylinder. Whenadding small amount of various alcohols,the crystal morphology of the product was flat clam, the crystallinitywas high and particle size of zeolite L increased obviously. Increasing ethanol amount in a certain range,thecrystallinity was decreased and zeolite L with different shapes was obtained.
JIANGDeng.ga01,PENG Chon91,PENGChuang2,WUJian3,ZHANG Yah3
Abstract: In thispaper,the effect ofmass fraction of K·Resin with the range from 10%to50%onthe optical andmechanical properties of polystyrene(PS)/K—Resin wasstudied by melting mixing method,and the surface morphology of the cross-section of impact sampleswere analyzed withSEM.The results showthatwith the increase of K-Resin’S mass fraction from 10%to 50%,the haze of PS/K-Resin alloy can be decreased to 11%from24.6%while the transmittance is almost the same as pure PS.only change from 86.5%to 85.6%.indicating that the optical match of PS and K·Resin is good.The results of mechanical properties and SEManalysis show that with the increase of K·Resin’S mass fraction in the alloy,the impacttoughness of the alloy material and the elongation at breakgenerated by tension both increase,the impact toughnesscan be increased to 4.65 kJ/m2 from 1.93 kJ/m2 andthe elongation at break generated by tensioncan be increased to 14.5%from 1.5%.showinganobvious plastic deformation morphology.
WANG Wei-shu’ ,LI Shuai-shuai’,ZHOU Jun-jie’,BI Qin-cheng’
Abstract: In view of the temperature characteristics of water wall in 350MW supercritical pressure boiler ofLinzhou thermal power plant,the temperature fields of rectangular fins water wall were numerically studied bythe finite volume method , and the spiral membrane water-wall temperature in the lower furnace was analyzed.According to the calculation results,temperature of spiral water-walls increases with the increase of the heightof furnace. The highest temperature,which occurs at the facing flame outer of water wall tube or the fin’send,is less than 440 C and does not exceed the permitted value of the metal. Both the highest temperatureand the maximum temperature difference increase with increasing the furnace load. As the thermal deviationcan be effectively reduced by using spiral water-wall,the temperature of water-walls and the temperaturedifference of working medium between each tube are very small along the width direction of the furnace.
MA Xin.1ing1,WANG Huil1,2,WEIXin—li1,MENG Xiang.rui1,YANG Kai.xuan1
Abstract: Flue gas waste heat of utility boiler was calculated.Based on flue gas as heat source and R245fa asworking fluid,thermodynamic analysis was carried out to waste heat power generation,and the optimal opera-tion parameters and generating capacity were determined.RETScreen was applied to analyse the investment in-come and benefit analysis of energy saving and emission reduction. The results show that generating capacity ofwaste heat unit is 47 ,502 MWh/a, the emission reductions of CO, is 42,419 ta. Under the condition of ini-tial investment costs 6,500 RMB/ kW and debt ratio 65% , equity payback only needs 1.1 years , energy pro-duction cost is 0.14 RMB/kWh,CHG reduction cost is 291RMB/tCO,.During operation period of 30 years,the cumulative cash is expected to be 431 million RMB.
JIA Shan-po,ZHAO You-qing,XU Cheng-xiang
Abstract: In this paper, the multi-reference frame(MRF ) and standard h - s turbulent model were used tosimulate the flow pattern and mixing characteristics in the stirred tanks with double layer straight impeller,double 45° inclined impeller and double layer straight and inclined combined impeller. The results showedthat double layer combined impeller can enhance the turbulence and mixing of the upper fluid and lower one inthe stirred tank.Moreover,compared with the double layer straight impeller, double layer combined impellercan save 37.91% of stirring power and reduce 50.48% of mixing time. Furthermore , compared with the feed-ing patterns from the fluid surface and the lower blade, the feeding pattern from the upper blade can obviouslysave the mixing time and improve the efficiency of mixing.
JI Zhan-ling1,2
Abstract: Based on heat transfer theory with phase change of multilayer board,thermal analysis was imple-mented for metal honeycomb sandwich plate with finite element method ( FEM).The research of phase changeproblem undexr high temperafure load was carried out.The computing results show that honeycomb sandwichplate has good heat insulation performance, the maximum tcmperature difference was more than 450 ℃ bc-tween the inside and outside surface;temperature field distribution in the honeyeomb core layer is not com-pletely identical to the other four layers ; it is different that each layer is influenced by the internal devices ; theouter skin begins to form the solid-liquid phase change after loaded 18s,the outer glue starts to produce solidliquid phase change aiter loaded 11s , and has already large area of gas-liquid phase transition to 14s , damagearea and damage degree are increased continuously. It has been better simulated with FEM that temperatureficld distribution laws,phasc transition failure process and its cvolution of thc complcx strucetures under hightemperature load.
LIU Hong-ying,YE Song
Abstract: The maximum nominal particle size of large size asphalt mixture is generally greater than 26.5 mm.The asphalt mixture paving thickness is up to 12 ~ 18 cm.The construction technology of the large size asphaltmixture especially compaction technology are quite different.The paper evaluated the cooling law of differenttypes of large size asphalt mixture using the indoor simulated cooling temperature test. The results show thatlarge size asphalt mixture surface cooling rate was greater than HMA,temperature difference between the sur-face and the middle of the mix can reach 15 ~ 25 ℃, and then keep the surface temperature until the rollingfinishing temperature ,thus extending the effective compaction time;the large size asphalt mixture paved thick-ness larger ,thermal energy storage longer,and no sensitive to temperature segregation than the normal asphaltmixture. The environment temperature and paving thickness of large size asphalt mixture have a great influenceto cooling law , while the gradation type of impact is relatively much smaller.
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