西南交通大学学报

State of Arts of Research on Rail Grinding

JIN Hua-Song, DU Xing, GUO Jun, CUI Da-Bin

2010, 23(1): 1-11. doi: 10. 3969/.j issn. 0258-2724. 2

[Abstract](1628)

PDF 1653KB(1034)

Abstract:
A detailed introduction to the existing theories and techniques of rail grinding and their application practices was presented. The interactions between rail grinding and rail rolling contact fatigue, railwear, noise and rail lubrication, aswell as theirmodels, were discussed. Based on the existing economicmodels for railgrinding, amodified economicmodelwas proposed, with the costs of depreciation of grinding equipment incorporated. Suggestions about researches in the future are presented: developing a computer program based on rail grinding practices to optimize rail grinding profile, investigating an optimization model that integrates the indexes of vehicle-track coupling dynamics and grinding costs, optimizing rail grinding procedures under differentworking conditions.

Influences ofW heelsetM isalignment on Running Safety ofRailway Vehicles

ZHANG Wei-Hua, CHE Mao-Ru, JIN Hua-Song, Shu-Min-Hao

2010, 23(1): 12-16. doi: 10. 3969/.j issn. 0258-2724. 2

[Abstract](1304)

PDF 739KB(683)

Abstract:
To investigate the influencesofwheelsetmisalignmenton running safety of railway vehicles,a dynamic vehiclemodelwithwheelsetmisalignmentwas setup. As an example of a high-speed train running on the tangent track, the influences ofwheelsetmisalignment on running safetywas analyzed by simulation. Analysis result shows that the influence of the parallelism error is significan,t so that much care is necessary during installation; and thatof the diagonal error ismuch less significant.

M ixed FEM ofB-SplineW avelet on Interval for Beam Structures

GUO Shi-Wei-, Lin-Jian-Hui

2010, 23(1): 17-22. doi: 10. 3969/.j issn. 0258-2724. 2

[Abstract](1442)

PDF 709KB(578)

Abstract:
A mixed finite elementmethod (FEM) of B-spline wavelet on the interval (BSWI) for beam structures was proposed based on the generalized variational principle of beam structure and interpolation ofBSWI, and general equations for solving static problem, vibrationmodal problem and stability problem of long beams and elastic foundation beams were presented. The deflection and momentwavelet parameters for common boundary conditions of beamswere obtained from numerical features of interval boundary of BSWI functions. The proposed method directly gets deflection and momentofbeam structures at the same time, and overcomes the shortcoming of low accuracy in beam moment calculation ofdisplacementFEM. Numerical results show that the proposedmethod increases beam moment calculation accuracy by 10. 9% compared with displacement FEM of BSWI, demonstrating its feasibility and high accuracy in applications to beam structure problems.

Current Properties ofW ire ElectricalDischarge M achining ofP-Type Solar Silicon

QIU Meng-Bei-, Liu-Zhi-Dong-, Hong-　Wei-, Tian-Zong-Jun-, Huang-Yin-Hui

2010, 23(1): 23-27. doi: 10. 3969/.j issn. 0258-2724. 2

[Abstract](726)

PDF 917KB(452)

Abstract:
In order to improve the efficiency ofwire electricaldischargemachining (WEDM) of solar silicon, a diode-resistance (DR) circuitmodel forP-type solar siliconWEDM was created to analyze the currentproperties under constantvoltage power supply. Theoretical analysis reveals that the circuit current is determinedmainly by the diode at the discharge end and the body resistance ofsilicon. W ith the discharge continuing, the current is blocked by the increase of avalanche voltage of the diode due to high temperature, but isboosted by the decrease ofbody resistance due to heattransfer. As a result， aU-type discharge current curve is generated; .i e., the discharge current is high on the both sides and flat in the middle. To verify the theoretical analysis, a P-type solar silicon with resistivity of 2. 1cm wasmachined byWEDM in experiments, and a single pulse discharge currentwaveform was picked up. The experimental results show that the discharge current started from 4 A, then dropped to 3. 2 A, and rose to 5. 2 A at the end of discharge, which confirms the discharge current characteristics of the solar silicon deduced by theoretical analysis.

Key Technologies in H igh-Speed Railway TurnoutDesign

Wang-　Beng, CHEN 　Rong, CHEN Xiao-Beng

2010, 23(1): 28-33. doi: 10. 3969/.j issn. 0258-2724. 2

[Abstract](1500)

PDF 906KB(825)

Abstract:
Based on the wheel/railmulti-point contact in turnout zone, a dynamic design theory for high-speed railway turnoutwas established and several creative designsweremade, such as separated semi-tangent switch plane linetype, horizontal hidden nose structure of turnout frog, short transitional top surface figure of the switch rai,l and track stiffness of turnout with even elasticity. W ith the harmony between vertical and lateral deformation of long rail components taken into accoun,t a transition locking structure for large expansion volume, an ending structure of the switch, a nose rail thatboth transfers longitudinal force efficiently ndmaintains turnout regularity, and a fastener system suitable forboth ballast and ballastless trackwere developed to solve the transition choking problem of jointless turnou.t In order to control the insufficient transition displacementof the long rail components to ensure the high regularity of turnout and its locking reliability, a transition design method for long rail components and double limb elastically bendable turnout frog structure was established using the finite elementmethod (FEM), a new roller sliding platform was developed, and the transition traction point layout and stroke designwere optimized.

Crack CalculationM ethod and Influence Factors for Continuously Reinforced Slab

Lin-Juan-Juan, LIU Hua-Yi, DIAO Ping-Dui

2010, 23(1): 34-39. doi: 10. 3969/.j issn. 0258-2724. 2

[Abstract](1326)

PDF 762KB(648)

Abstract:
In order to research the development mechanism of cracks in continuously reinforced concrete slab of twin-block ballastless track, a theoreticalmodelwas put forward based on the bond- slip constitutive relation between steelbars and concrete. Crackwidth, crack space and steelbarstress were calculatedwith thismode,l and their influencing factors, such as reinforcement ratio, steel bar diameter and concrete tensile strength, were analyzed. The analysis results show that crack space increaseswith the increase of steel bar diameter and the reduction of reinforcement ratio; crackwidth decreaseswith the reductions of concrete tensile strength and steel bar diameter and the increase of reinforcement ratio; and steelbar stress in the crack section should notexceed its tensile strength, and the key influencing factors for steelbar stress are reinforcement ratio and concrete tensile strength.

Influence of SteelArch Corrosion on Security of Supporting System of Sub-sea Tunnel

WANG Meng-Nian, LI Hai-jun, ZHOU Guo-jun

2010, 23(1): 39-44. doi: 10. 3969/.j issn. 0258-2724. 2

[Abstract](1158)

PDF 735KB(718)

Abstract:
To raise the supporting system security of large cross-section sub-sea tunnels, FEM (finite elementmethod) wasused to analyzeXiamen sub-sea tunne.l The effects ofsteelarch corrosion on the load-bearing capacity of steel arches and the securities ofpreliminary lining and secondary liningwere investigated under two conditionswith orwithouthydraulic pressure. The research indicates thatwhen steel arch corrosion rate is up to 80%, the load-bearing capacity and the bond force between steel arches and concrete will completely lose. W ith the corrosion of steel arches, the reduction factor of moment is a quadratic function of the corrosion rate, while the reduction factor of axial force is basically a linear function of the corrosion rate. Under the conditionwith hydraulic pressure, the safety factor of sidewall and arch crown decreases about6. 6% and 6. 4% respectively for preliminary lining and secondary lining, while it reduces approximately 5. 5% and 3. 4% respectively for preliminary lining and secondary lining under the conditionwithouthydraulic pressure.

Influence ofM etro Tunneling in SoftC lay Strata on Underground Pipeline

QI Tai-Yue-, Gao-　Bei-, Tan-Dai-Meng

2010, 23(1): 45-53. doi: 10. 3969/.j issn. 0258-2724. 2

[Abstract](1270)

PDF 1349KB(673)

Abstract:
To reduce the influence ofground surface subsidence caused bymetro tunneling in softclay strata upon underground pipelines, the numerical simulationmodel in software FLAC3Dwas applied to compare three tunneling methods, .i e., pumping, dynamic pumping and un-pumping tunneling methods, through considering the compounding effectof fluid-solid coupling and tunneling process and the safety control standard of pipelines. The research result shows that the un-pumping tunneling method is the most effective one, thismethod being adopted in the construction of Shenzhen metro tunne,l so thatgas pipelines below the tunnel ran safely in the construction process.

Quantification of Seism ic Performance Levels for Urban Viaduct

LIU Yan-Hui, Diao-Shi-Chun, Jiang-Shi-Zhong

2010, 23(1): 54-59. doi: 10. 3969/.j issn. 0258-2724. 2

[Abstract](1421)

PDF 724KB(710)

Abstract:
By taking a urban viaductas the research objectand on the premise of the determinationsof performance levels ( integrity, almost integrity, slightdamage, oderate damage and serious damage) and performance indexes (damage index expressed by the displacement ductility coefficient of bridge pier top), the quantitative process of performance levels was emphatically discussed to realize the performance-based seismic design ofurban viaducts. Its concrete steps are to propose the corresponding relationship between each performance level and limits of concrete compression strain and steel tension strain in the plastic hinge ofbridge pier, establish the relationship between each performance level and the displacement and the displacement ductility coefficient of bridge pier top, and set up the quantitative relationship between each performance level and the damage index. A comparisonwith the current researches indicates that the proposed performance indexes are rational.

Image ObjectDetection inM onitoring ofPantograph Slippers

Chen-Wei-Rong, FENG 　Qian, ZHANG 　Jian, XU Guo-Wang, LI 　Zhe

2010, 23(1): 59-64. doi: 10. 3969/.j issn. 0258-2724. 2

[Abstract](1203)

PDF 1375KB(728)

Abstract:
Digital image process technique was used to monitoring of pantograph slippers, and the work principle and structure of a pantograph swireless image monitoring system were introduced. An image object detection algorithm for pantograph slippers, composed of rough detection and exact detection, was proposed. W ith this algorithm, the targetpantograph slipper can be detected based on edge detection, morphology, radon-transform, clustering andHough-transform, and its position can be found exactly from a complex image. The test results show that this algorithm is hardly affected by complex background, asymmetric illumination, noises and so on, and an accuracy of 85% can be reached.

Networked Control System s Based on New Sm ith Predictor

Du-　Feng, JIAN Qing-Quan, DU Wen-Cai

2010, 23(1): 65-70. doi: 10. 3969/.j issn. 0258-2724. 2

[Abstract](1218)

PDF 657KB(488)

Abstract:
In order to effectively restrain the influence of network delays on the performance of networked control systems (NCS), a new Smith predictorwith regard to the delays of network and controlled plantwas proposed. This new Smith predictordoes not include predictionmodels ofnetwork delays, and network delaysdo notneed to bemeasured, estimated or identified on line. As a resul,t it is suitable for the networked control systemswith random, time-variant and uncertain network delays. The simulation results show that networked control systems based on the new Smith predictor have a strong robustness, a desirable dynamic performance and an anti-jamming abilitywhen network delays aremore than one even dozens of sampling periods.

Multi-objective Train Operation Optim ization Based on Particle Swarm Algorithm

Tu-　Jin, HE Zheng-You, JIAN Qing-Quan

2010, 23(1): 70-75. doi: 10. 3969/.j issn. 0258-2724. 2

[Abstract](1966)

PDF 859KB(740)

Abstract:
To reveal the essence ofmultiple objectives of train operation, amulti-objectivemodel for train operation was established and solved by using the multi-objective optimization method. Improvement and keeping diversity strategies were introduced to overcome the deficiencies of the existingMOPSO (multi-objective particle swarm optimization) algorithms. Simulation results show that the improvedMOPSO algorithm can generatemore than one train control strategy during a time running simultaneously, display changes in performance indices with the control strategies and decrease the shifting number of control serials sharply. Furthermore, fine tradeoff among energy cos,t running time and stopping atadequate pointcan be obtained, as a resul,t the strategy suited to the train running can be selected to get an anticipated resul.t

MulticastQoS Routing Technology Based on Fixed-Length Frame

HONG Hai-Ying, CENG Hua-Shen, LI 　Ji

2010, 23(1): 76-81. doi: 10. 3969/.j issn. 0258-2724. 2

[Abstract](1098)

PDF 895KB(597)

Abstract:
To effectively utilize network resources and balance the load, amulticastmechanism based on a fixed-length physical framewasproposed, and aQoS (quality ofservice)-awaremulticastrouting algorithm was designed, named as MRBP (multicast routing load-balancing algorithm based on Ethernet-oriented physical frame timeslotswitching). This algorithm minimizes the delay and balances the load to construct amulticast treewith a small delay and utilige network resources more reasonably under the condition of satisfying the bandwidth and delay constraints. Simulation results show that a multicast tree constructed by the proposed algorithm instead of other approaches has a good load- balancing performance and is able to provide aQoS guarantee.

Listless Image Coding Algorithm Based on Region of Interest

BO 　Bei-, Yang-Gen-Qiang-, Sun-　Ning

2010, 23(1): 82-86. doi: 10. 3969/.j issn. 0258-2724. 2

[Abstract](899)

PDF 1221KB(500)

Abstract:
To reducememory requirementof the ROI (region of interest) coding algorithm based on lists, a new ROI coding algorithm based on listless zero-tree was proposed. In the process of SPIHT (set partitioning in hierarchical trees), signed bit planes are used to record the significance information ofcoefficients and sets. TheROI is encoded firs,t and the significance information ofNROI (non-region of interest) is recorded in queues, so that the NROI can be encoded with restored significance information from the queues. The simulation results show that the proposed algorithm can getbetter reconstructed quality than the coding algorithm based on scaling ROI coefficients. It can achieve accurateROI codingwithout scaling upROI coefficients, and needs only one-tenth ofmemory required by theROI separate coding algorithm based on lists when the coding rate is 1 bpp (bits/pixel).

Impact of Integrated GroundingW ire on Traction Return Current in Direct Power Supply System

DONG An-Beng-, Zhang-Xue-Yuan-, Deng-Meng-Li-, Chen-Ji-Gang-, Tun-An-Ning

2010, 23(1): 88-94. doi: 10. 3969/.j issn. 0258-2724. 2

[Abstract](1148)

PDF 795KB(531)

Abstract:
In order to investigate the distribution of traction return current for high-speed and heavy-load railways, the equivalent impedances of rail and integrated grounding wire were calculated by analyzing their electrical circuits. W ith the equivalent impedances, the ratio of traction currents in the rail and integrated groundingwirewas obtained. A calculational resultbased on the typicalparameters ofballastless track ofShuining-Chongqing railway indicates that themaximum current flowing through the integrated grounding wire is 19. 7% of the traction return curren,t and it is consistentwith the testing result.

Multi-constrained Routing Algorithm Based on M obile Agent forM obile Ad Hoc Networks

Zhang-　Yi, FENG 　Li, CHEN 　Wei, ZHANG Xiu-Mei

2010, 23(1): 94-98. doi: 10. 3969/.j issn. 0258-2724. 2

[Abstract](873)

PDF 743KB(480)

Abstract:
In order to solve the problem with the constraints of energy and available bandwidth, a routing algorithm based onmobile agentswas proposed. Itusesmobile agents to collect the information ofallmobile nodes. This algorithm has a strong routing stability because itselects linkswith the largest link expiration time. A multi-path strategy is adopted to reduce the time consumption of rerouting. Furthermore, the nodewithmore remaining batterywillbe first selected to extend the survival time of network. Experimentswere conducted with network simulatorNS2 to evaluate the performance of the proposed algorithm. The experimental results show that the proposed algorithm has a higher packet deliver ratio and a lower average end-to-end delay than the AODV ( ad-hoc on-demand distance vector) routing.

Principle Analysis and Implementation ofVoltage Control of Hybrid Excitation SynchronousGenerator

FU Xin-He, JU Ji-Bin, JI Wen-Juan

2010, 23(1): 99-104. doi: 10. 3969/.j issn. 0258-2724. 2

[Abstract](996)

PDF 707KB(539)

Abstract:
A novel hybrid excitation synchronous generator (HESG) was developed to solve the problem that the output voltage is uncontrollable in permanentmagnet generator. The magnetic flux distribution of both the permanent magnet section and the excitation section in the HESG were computed using finite elementmethod. According to the demand for the output voltage, a control strategy for the excitation regulation system wasmade, and the operation process of this system was discussed. To verify the output voltage control capability of theHESG, a 2. 5 kW generator and its regulation circuit were designed and produced, and then tested by experimen.t The experimental results show that forno-load running, the outputvoltage of theHESGwas equal to the resultantelectric potential of the permanentmagnet section and the excitation section; and that for load running, the HESG was able to vary the gap flux tomaintain the constant terminalvoltage (135V) by adjusting the excitation current as the load increased.

M odel and Algorithm for Taking out and Placing inW agons in Shunting Operation on RadialPrivate Lines

王慈光

2010, 23(1): 104-111. doi: 10. 3969/.j issn. 0258-2724. 2

[Abstract](1053)

PDF 867KB(607)

Abstract:
To find the reasonable sequence, momen,t and batch number of taking out and placing in wagons in shunting operation on radial private lines, a model forwagonstaking-out and placing-in operation on radialprivate lineswasbuiltby combining qualitative and quantitative analysis. Then, the methods to construct and compute the solution of the model were elaborated, and an effective ant colony genetic algorithm (ACGA) was designed to search the optimal solution. The model and its algorithm are suitable to solve the problem of taking out and placing in wagons on radial private lines with various kinds ofwagon flows, and they can generate adaptive organizationmodes of taking-outand placing-in operations to achieve a globally optimal operation scheme, which overcomes the shortcomings in the shunting operation using a fixed organizationmode. An example simulation shows that the batch numberof taking-outand placing-in operationswas reduced from 30 to 18, and that the total time that eachwagon spends at the stationwas saved effectively.

Fleet Planning Approach Based on Optim ized FleetCapacity Allocation in Airline Networks

Sun-　Hong, ZHANG Pei-Wen, HONG 　Yu

2010, 23(1): 111-115. doi: 10. 3969/.j issn. 0258-2724. 2

[Abstract](2109)

PDF 680KB(702)

Abstract:
The proposed approachwasbased on predicted statisticsofairline transportproduction, and its optimization objectivewas tomaximize the profit of airline companies. Fleet capacity allocation on each air route was optimized considering the technical and economic properties of each airplane type and traffic demand, flight frequency on each air route, and available flight time ofairline flightcrews. The optimal fleet composition was determined based on average utilization ratio of each fleet type. A simulationwasmade using LINGO software with input of 5 fleet types and 60 routes, and the result shows that the proposed approach is robust to the fluctuation of traffic demand ofmarket.

Risk Analysis ofFlightConflict in Low Altitude Airspace

WANG Shi-Jin, DUO 　Dong

2010, 23(1): 116-123. doi: 10. 3969/.j issn. 0258-2724. 2

[Abstract](1049)

PDF 983KB(857)

Abstract:
In order to determine the safe separation and risk probability of aircrafts in low altitude airspace, a collision avoidancemathematicmodel foropposite and intersecting flights at the same level was builtunder the constraints of flight rules, visibility requirements, response time, aircraft speed, and aircraft turn bank angle or climb angle, by following the ICAO ( International CivilAeronautics Organization) standards, CAAC (CivilAviation Administration of China) regulations, aerodynamic principles, and see-and-avoid principle. Then, based on the human cognitive reliability (HCR) theory, a response failure probabilitymodel of pilotswas also buil.t Numerical analysis results show that in low altitude airspace, there is a certain risk probability of safety separation violation between two head-on aircrafts, but the cross-converging aircrafts at the same level can safely avoid collision.

M odified BPR Functions for TravelTime Estimation of Urban ArterialRoad Segment

JIANG Gui-Yan, Li-Ji-Wei, Zhang-Chun-Qi

2010, 23(1): 124-129. doi: 10. 3969/.j issn. 0258-2724. 2

[Abstract](1040)

PDF 935KB(521)

Abstract:
To increase the estimation accuracy of average travel time for urban arterial roads, three kinks ofmodified BPR functions, namely accumulative volume BPR functions for general states, BPR functions specially calibrated for a given state and accumulative volume BPR functions for a given state, were proposed using the data of section volume collected by loop detectors installed in the upstream of the road segments. Simulation results for the same simulation scenario show that the accumulative volume BPR functions for general states significantly outperform the classical ones, and the twomodified BPR functions for a given state are even better, with the smallest average estimation errorof8. 05% obtained by the accumulative volumeBPR functions fora given state under themedium heavy traffic state.

Beeline Bus Stop Type Selection Based on Analysis of Influence on Traffic Flow

HU Wen-Ting, CHEN 　Jun, MO 　Xia

2010, 23(1): 130-135. doi: 10. 3969/.j issn. 0258-2724. 2

[Abstract](1035)

PDF 795KB(493)

Abstract:
For type selection ofbeeline bus stop, the influences ofvirtual-bay bus stop (.i e., a bus stopwith reverse harboron line) and common beeline bus stop on traffic flowwas compared according to the investigation data from a bus stop in Nanjing in terms of the influential factors such as traffic load, bus dwell time, and bus arrival rate at the stop. Then, an overall traffic flow speed modelwas established under the influence ofa virtual-bay bus stop along side divider. Thismodel can be used to calculate the delay of traffic at the bus stop, which, togetherwith the traffic capacity, can be used to optimize the selection ofbeeline bus stop types. Calculation results based on thismodel show that for single lane roads, virtual-bay bus stop works better; for two-lane roads, type selection needs to be made according to multiple traffic factors such as traffic load; and for three-lane roads, given the average dwell time ofbuses shorter than 1 min, common beeline topwins.

Calculation of Speed Lim it on Foggy Days

SHI Gui-Fang-, Yuan-　Gao-, Cheng-Jian-Chuan

2010, 23(1): 136-140. doi: 10. 3969/.j issn. 0258-2724. 2

[Abstract](1248)

PDF 580KB(707)

Abstract:
Experiments were conducted with professional equipments atmotordrome to acquire the braking characteristic data ofdriverswhomeetunexpected obstacles. The results show thata braking- reaction time of2. 0 s in good road traffic conditions and 2. 5 s in general road traffic conditions satisfy mostdriversdemands. A calculation method of speed limit on foggy days was then developed by simplifying the braking process into the braking-force growing phase and the ontinuousbraking phase, to calculate the speed limits in differentvisibility conditions. The calculated values and recommended values ofspeed limits forvarious visibilities provide a theoreticalbasis for controlling the speed limitof vehicles on foggy days. The recommended values are approximately equal to those specified in the speed limitguides ofUtah, USA and bigger than those specified in the Law of the PeoplesRepublic ofChina on Road Traffic Safety.

Nonlinear Control for Ship Course-Keeping Based on Lyapunov Stability

ZHANG Xian-Ku

2010, 23(1): 140-143. doi: 10. 3969/.j issn. 0258-2724. 2

[Abstract](1085)

PDF 525KB(530)

Abstract:
To simplify the design process ofnonlinear controller for ship course-keeping, a Lyapunov energy function was derived. The simplified design process reduces 2 design steps into 1, has less parameters to be tuned, and avoids canceling the nonlinear items. The simulation researchwas carried outby taking a ship as an example. The results showed that the controllerwas robust and exhibited good performances in terms ofmain control indexes, and the rudder angle and rotation rate were desirable.

Design and Realization ofAssessment System for G iant Panda sHabitat

YANG Wu-Nian, XIE Hong-Bin, JIAN 　Ji, NA 　Xi

2010, 23(1): 144-149. doi: 10. 3969/.j issn. 0258-2724. 2

[Abstract](832)

PDF 1337KB(504)

Abstract:
TheWenchuan earthquake led to serious damage to the ecological environment of giant pandas habitat in the western Sichuan Plateau. For scientific, fast and real-time assessment of giant pandas habita,t an assessment system, based on the landscape ecology and spatial analysis, was represented to estimate giantpandas habitatwith theVB.NETplatform and theArcEngine software. In this system, a newmethodwasproposed to extractcore patch and potential corridorwith a suitable size in grids. The research provides a convenient way for better decision-making about giant panda protection by the habitat assessment and landscape pattern design ofnature reserve.

M odified GPS AmbiguityW hite-Filtering Algorithm

HUANG Zhang-Yu, CHEN Su-Juan

2010, 23(1): 150-155. doi: 10. 3969/.j issn. 0258-2724. 2

[Abstract](1183)

PDF 874KB(451)

Abstract:
In order to improve the decorrelation ofGPS (global positioning system) ambiguity, the white-filtering decorrelation algorithm wasmodified on the basis ofanalyzing the existingwhite-filtering decorrelation algorithms. In this modified algorithm, sequencing of elements in the ambiguity covariance matrix is appended based on a white-filtering process to ensure the validity of matrix transform and improve the effect of decorrelation and the quality of ambiguity space searching. The numerical simulation indicates that themodified algorithm can be used succsessfully to the calculation of any dimension data, has a good applicability and decorrelation and can improve the efficiency of kinematic ambiguity resolution.

Determ ination ofNitrite with FI-Spectrophotometric Analysis

Gong-Zheng-Jun, CHEN Guo-He, XIAO Xin-Feng, ZHANG Xin-Shen

2010, 23(1): 156-159. doi: 10. 3969/.j issn. 0258-2724. 2

[Abstract](766)

PDF 584KB(422)

Abstract:
A new flow-injection catalytic kinetic spectrophotometric method was proposed to rapidly determinate trace amounts ofnitrite. The proposedmethod is based on the accelerating effectofnitrite on the reaction between potassium chlorate andmethylene blue in strongly acidicmedia and combines the flow injection. Under the selected conditions, the calibration graph is linear in the nitrite mass concentration ranges of5 to 150g/L and 150 to 1 000g/L, and the detection limit is1g/L. The relative standard deviation is respectively 3. 1% for 10g/L nitrite (n, number of samples, is 11) and 4. 6% for100g/L nitrite (n=11). The proposedmethod has been applied to the determination ofnitrite in natural water samples, the standard deviation is 1. 1% to 3. 4% and the recovery is 97. 6% to 100. 3%.

Experimental Study on Leachate TreatmentUsing Sem i-aerobic Aged Refuse Bioreactor

ZHANG Ai-Beng-, Liu-　Dan-, Liu-　Yong-, Wang-Yu-Qi

2010, 23(1): 160-165. doi: 10. 3969/.j issn. 0258-2724. 2

[Abstract](1012)

PDF 915KB(439)

Abstract:
A semi-aerobic bioreactor, filled in with aged refuse in a laboratory, was used to treat leachate by once injection. As a resul,t in the case of a hydraulic load of40 L/d, a COD (chemical oxygen demand) organic load of480 g/d and an ammonia nitrogen (NH3-N) load ofabout12 g/d per cubicmeter aged refuse, the COD removal efficiencywas over 92%, and the organic pollutantswere reduced from 26 kinds to 10 kinds after treatmen.t At the same time, the removal efficiencies of the ammonia nitrogen and the totalnitrogen (TN) were 98% and 96%, respectively. W ith the ammonia load increasing, when the influent concentration ofTN in the leachate was 523 to 2 611 mg/L, the removal efficiency was kept between 75% and 96%. Therefore, the bioreactor can simultaneously realize efficient removaloforganic and nitrogen pollutants in the leachate, and tolerate a large nitrogen load.

Search Advance Search

Journal Search

Search Type

NewsMore

instruction for authors

Read this journal

LinksMore

2010 Vol. 23, No. 1