Volume 35,Issue 7,2012 Table of Contents

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  • 1  Design and simulation of electromagnetic parking brake embedded in wheel motor
    CHEN Qiping SHU Hongyu QU Feijun XIE Xin XIE Anyuan
    2012, 35(7):1-6. DOI: 10.11835/j.issn.1000-582X.2012.07.001
    [Abstract](1791) [HTML](0) [PDF 3.12 M](1031)
    Abstract:
    Based on the electromagnetic theory and the work principle of electromagnetic parking brake,a new structure power breaker electromagnetic brake is designed,which is low energy consumption and embedded in in wheel motor,and a kind of analysis computation method is proposed. Through the analysis of magnetic circuit of electromagnetic brake,the mathematical model is established. A three dimensional finite element model is established via Ansoft software with the purpose of analyzing the electromagnetic property and work performance of electromagnetic brake,as well as simulating the dynamic work process of electromagnetic brake. By profoundly investigating the intricate internal magnetic field strength and power density distribution of the electromagnetic brake,the current research has obtained the exciting coil with time curve,electromagnetic force with work air gap curve and the armature displacement with time curve,etc. The conformity of the final simulation results with the experimental data indicates that the electromagnetic finite element method is accurate and reliable to analyze the electromagnetic property of electromagnetic brake,which can meet the requirements of sensitivity,reliability and specialization in electric scooter parking brake system.
    2  De nosing method based on multiscale morphological filter optimized by particle swarm optimization algorithm
    DONG Shaojiang TANG Baoping CHEN Fafa
    2012, 35(7):7-12. DOI: 10.11835/j.issn.1000-582X.2012.07.002
    [Abstract](1057) [HTML](0) [PDF 2.11 M](770)
    Abstract:
    The traditional morphological filter is difficult to remove the noise of the vibration signal,because the signal has the characteristics of shocking and nonlinear. A new method based on multiscale morphological filter optimized by particle swarm optimization algorithm is proposed. The multiscale morphological filter is constructed according to the character of morphological algorithm. The particle swarm optimization algorithm is used to select the adaptive structure element,which plays an important role in morphological filter,achieving to get the optimal morphological filter. The signal is filtered through different scales of morphological filters and the noise removed signal is gotten through weight algorithm. The simulated signal and the bearing fault signal are analyzed,and the results show that the optimal morphological filter works better in removing noise and can effectively reduce the noise of the mechanical equipment.
    3  Development of control strategy for a series parallel hybrid electric bus based engine efficiency optimization
    LIN Xinyou SUN Dongye YIN Yanli HAO Yunzhi
    2012, 35(7):13-18. DOI: 10.11835/j.issn.1000-582X.2012.07.003
    [Abstract](1185) [HTML](0) [PDF 2.77 M](872)
    Abstract:
    To improve efficiency of engines,according to the characters of a novel series parallel hybrid electric bus(SPHEB) to define the operation area of ice,a kind of power balancing control strategy is adopted and the battery power is used as a variable to optimize the efficiency of fuel converter,and the PI control is implemented to control the SOC balance. To validate the proposed strategy’s effectiveness and reasonableness,a forward model is built based on simulink and the simulation results demonstrate that the proposed strategy can successfully improve the efficiency of fuel economy up to 6.74% compared with that of equivalent fuel minimum control strategy,while the battery SOC is also limited in the desired range.
    4  The main loop and servo loop structure control strategy of ESC
    ZHANG Wei WANG Weida DING Nenggen LI Chunli
    2012, 35(7):19-24. DOI: 10.11835/j.issn.1000-582X.2012.07.004
    [Abstract](1119) [HTML](0) [PDF 2.04 M](2228)
    Abstract:
    Aiming at the control of electronic stability control system(ESC)which can enhance the handling stability in limited condition,the hierarchical control structure control strategy of ESC including main loop and servo loop is proposed. The first order sliding mode control is used in the main loop and the sliding mode plane and control law are designed. The output of main loop is the accessional yaw moment. The nine points with five states control which can approximately simulate human thinking is used in the servo loop. The brake pressure is controlled by the servo loop aiming at the desired slip rate and the accessional yaw moment is generated by brake force. The driver in the loop simulation bench is designed and the online test of the control strategy is carried on. The test results indicate that the handling stability and active safety are enhanced remarkably by the ESC control strategy in the drive condition of low adhesion road and driver handling vehicles immoderately,and the testing facticity and the pertinency of developed control strategy are improved by the driver in the loop simulation.
    5  Numerical simulation of flow field dynamics characteristics for a novel twin screw kneader
    WEI Jing SUN Xujian SUN Wei
    2012, 35(7):25-31. DOI: 10.11835/j.issn.1000-582X.2012.07.005
    [Abstract](987) [HTML](0) [PDF 4.85 M](841)
    Abstract:
    The numerical simulation for dynamic characteristics of the flow field of a novel twin screw kneader is carried out. The numerical simulation model of twin screw kneader is established,and the three dimensional,isothermal and steady numerical analyses of non newtonian fluid are presented based on computational fluid dynamics(CFD)theory,and the characteristics under the conditions of different speeds and center distances,such as the distribution of pressure and velocity field,the maximum shear stress,the mass flow rate and so on,are studied. The research results show that:with increasing speed,the maximum flow pressure,the mass flow rate and the maximum shear stress increase; the maximum shear stress increases first and then decreases with increasing of center distance of the screw rotors,while the mass flow rate increases with increasing of center distance; but when the center distance reaches a certain degree,the mass flow rate is negative and the material appears serious reflux which can make the kneader stop working. The results provide a theoretical basis for performance prediction and reasonable designing for the novel twin screw kneader.
    6  Analysis and optimization of resistive cavitation property of annular groove within relief valve
    LIU Shun’an YANG Song CHEN Yanli HU Weiguo XIE Dantong ZHAO Wei
    2012, 35(7):32-36. DOI: 10.11835/j.issn.1000-582X.2012.07.006
    [Abstract](964) [HTML](0) [PDF 2.83 M](791)
    Abstract:
    RNG k ε turbulence model is adopted to simulate the cavitating flow of annular groove within relief valve,and the influence of structural parameters of annular groove on cavititaing flow field is analyzed. The analysis results show that performances of resistive cavitations increase with the rising of structural parameter θ when structural parameters R1and R2 are the optimal values. According to numerical simulation data of annular groove’s structural parameters,the surrogate models is obtained via the kriging calculated method,i.e. the objective function is the maximum gas volume fraction,the correlation function is the Guass function and constant regression model is applied to the likelihood function of surrogate models. The surrogate function is optimized by the improved PSO algorithm,and resistive caviatation property of the optimized structural parameters has higher efficiency compared with other ones.
    7  Testing and modal analysis on multi stage planetarygearbox housing of shield tunnelling machine
    XIAO Zhengming QIN Dationg WU Wenhui ZHOU Zhigang
    2012, 35(7):37-42. DOI: 10.11835/j.issn.1000-582X.2012.07.007
    [Abstract](1040) [HTML](0) [PDF 2.84 M](940)
    Abstract:
    The finite element model is developed for the multi stage planetary gearbox housing in shield tunnelling machine (STM), and the the eigenvalue problem is solved by using block Lanczos method, and then the low order natural frequencies and corresponding modes are extracted. Based on the theory of experimental modal analysis, the modal testing is made for the gearbox housing by pulse excitation method. The least squares complex frequency domain (LSCF) estimation method is used to analyze the modal data, and the natural characteristics of housing is obtained. According to the modal assurance criterion (MAC), the experimental modal parameters are validated. Modal analysis shows that the experimental data is coincided with analytical results, which indicates the accuracy of the theoretical model and testing method. The coupling sympathetic vibration is disappearing between the gears train and housing, the local vibration is large at the high speed side of gearbox housing, and the torsional mode is outstanding under operating condition. The research results provide theoretical basis and experimental support for the structural optimization of the gearbox of STM.
    8  Backlash control and compensation for internal meshing involute spur gears
    LI Junyang WANG Jiaxu XIAO Ke LIU Qiang
    2012, 35(7):43-48. DOI: 10.11835/j.issn.1000-582X.2012.07.008
    [Abstract](1197) [HTML](0) [PDF 2.44 M](921)
    Abstract:
    To best control the backlash of internal involute spur gears, the errors which influence the clearance in design and manufacture process are analyzed, classified and quantified. On the basis of realizing the formation mechanism and periodic change of errors, considering the feasibility of control and compensation of errors and minimum cost, this paper proposes a control and compensation method of gear backlash, including tooth thickness tolerance compensation based on equivalently modified gear, deformation compatibility design of gear, and the design formulas of minimum meshing center distance on the consideration of various errors. Then, by using the present method, two pairs of gear are taken for experiment by setting the module to 1, number of teeth to 45 and 40 respectively, precision grade to 7 and 6, respectively. The results show that the gear backlash was controlled in 3'with present method.
    9  The micro vibration analysis for the large aperture grating tiling device
    ZHOU Yi LIAO Yunfei LIU Youhai LUO Yuefei Wang Xiao ZHOU Hai
    2012, 35(7):49-53. DOI: 10.11835/j.issn.1000-582X.2012.07.009
    [Abstract](1148) [HTML](0) [PDF 1.99 M](950)
    Abstract:
    A new grating tiling device with 2×2 gratings is developed to obtain a large aperture grating. For the stability of the device impacted by the HVAC vibration, a dynamic finite element analysis model is established. The random vibration response of the model under the measured power spectral density as stimulus has been carried out by the ANSYS software, and the data has been compared to the experimental data. The results show that the device can meet the stability requirements in the work environment.
    10  A floating threshold quantization algorithm to suppressmixing interferences in partial discharge
    TANG Ju WU Mianzhi LI Wei ZHOU Jiabin ZHANG Xiaoxing
    2012, 35(7):54-60. DOI: 10.11835/j.issn.1000-582X.2012.07.010
    [Abstract](964) [HTML](0) [PDF 3.38 M](950)
    Abstract:
    Due to the obvious difference of energy distribution frequencies from partial discharge (PD) signal and its mixing interferences (white noise and narrow brand), we uses the characteristic that node decomposition coefficients of wavelet packet transform can effectively show the energy change of signals to build up a floating threshold quantization algorithm (FTQA) varying with the noise energy of PD decomposition coefficients. It makes the node thresholds under the optimal base various with the noise strength in decomposition coefficients to self adaptively reality the choice of optimal threshold to finely partition PD decomposition coefficients. For simulated and real PD signals with mixing interferences, the conditional global threshold quantization algorithm (GTQA) and the proposed floating threshold quantization algorithm are employed to suppress the mixing interferences in PD signals and compared, and the results show that the proposed algorithm has the stronger suppression ability to mixing interference on PD signal and keeps perfect PD waveform via suppression.
    11  A preventive control model for static voltage stability considering the power constraints of weak branches
    YAN Wei HU Xiuqiong YU Juan LI Wenyuan
    2012, 35(7):61-66. DOI: 10.11835/j.issn.1000-582X.2012.07.011
    [Abstract](1179) [HTML](0) [PDF 1.27 M](879)
    Abstract:
    The voltage instability of power system often occurs when the active power on one or more weak branches exceeds its transfer capability. A preventive control model for static voltage stability is proposed using the active power transfer capability of weak branches as static voltage stability constraints. A local line based voltage stability index is used to determine the critical contingencies, weak branches and transfer capability of each weak branch. A static security analysis method, which is based on DC power flow equations, is used to establish the non linear active power flow expressions on weak branches following each critical contingency. The active power constraints on weak branches can be obtained from the active power flow expressions and transfer capabilities of weak branches. A quadratic optimal model for preventive control including the proposed active power constraints on weak branches is presented. The simulation results for IEEEE14 bus system and IEEE118 bus system demonstrate the correctness and effectiveness of the proposed preventive control model.
    12  Investigation on microstructure and mechanical properties ofnano ceramic coating on AZ31 magnesium alloys
    GAO Zhengyuan PAN Fusheng
    2012, 35(7):67-71. DOI: 10.11835/j.issn.1000-582X.2012.07.012
    [Abstract](1262) [HTML](0) [PDF 2.03 M](827)
    Abstract:
    In order to improve the wear resisting property of magnesium alloy’s surface coating, Al2O3 nano ceramic coating on the surface of AZ31 magnesium alloy is prepared using the magnetron sputtering process. Influences of temperature, power and time on hardness of surface layer are discussed by orthogonal method. Morphology, phases and composition of coatings are analyzed by SEM, XRD and EDS. The results show that the time and power are important factors to affect hardness and wear resistance. The process parameters of 80 ℃,200 W and 3 h are the optimal sputtering process. Through this process, the thickness of nano Al2O3 coating on AZ31 is about 2 to 10 μm and the grain size is about 30 nm. The surface hardness of ceramic coating reaches up to 1 360 MPa, and increases more than 77.31% of the substrate hardness of nano Al2O3 coating.
    13  Effect of nitrogen on microstructure and properties of SWRH82B wire rod
    SHENG Guangmin WU Lili DENG Yongqiang WEI Fulong LI Zhengsong ZHANG Dongsheng YANG Maolin
    2012, 35(7):72-76. DOI: 10.11835/j.issn.1000-582X.2012.07.013
    [Abstract](1172) [HTML](0) [PDF 2.98 M](907)
    Abstract:
    The microstructure, mechanical properties, tensile fractures and the precipitation of the second phase of vanadium microalloyed wire rods with different nitrogen contents are studied by hydraulic universal testing machine, scanning electron microscopy(SEM) and transmission electron microscopy(TEM) . The results show that the interlamellar spacing of pearlite is smaller in high nitrogen steel; the high nitrogen steel has higher yield strength, tensile strength and lower elongation and reduction of area; there are more inclusions on the tensile fracture surfaces of the high nitrogen steel; and in high nitrogen steel, the size of precipitation, mainly precipitating at dislocation or the boundary of austenite, is finer than that of low nitrogen steel, what is more, fine V(C,N) particles are concluded in the precipitations.
    14  Analyses on stress and deformation of thin walled metallic round tube in edge incurving process
    NIU Weizhong
    2012, 35(7):77-82. DOI: 10.11835/j.issn.1000-582X.2012.07.014
    [Abstract](1274) [HTML](0) [PDF 1.65 M](853)
    Abstract:
    Consisting of three forming processes, i.e. edge incurving, flanging and deep drawing, tension driven internal inversion method is a new technology for shaping thin walled metallic round tube into a double layered tubular part with an annular bottom. Based on the study of edge incurving process of tubes, a number of analytical relations are established which reflect the influences of tube size, material properties, mould size, friction condition and scale factor m on the stress and deformation parameters of tubular part in the process before and after partial tube wall in the curling region has wrinkled. Also, some discriminants are proposed for judging if the tube wall in the curling region wrinkles and if the process is practicable for a certain tubular part. Example indicates that when m is in the scope of 0.7 to 0.8, the stress and deformation parameters calculated by formulas match those simulated by metal plastic forming simulation software DYNAFORM, and the conclusions derived from discriminants correspond well with the simulation and experiment results.
    15  The molecular structure and chemical bond properties of dimethylphenylsilanol studied by DFT/B3LYP
    ZHANG Zhengfu YU Qiuyan WU Lin SUN Lijun PENG Jinhui
    2012, 35(7):83-88. DOI: 10.11835/j.issn.1000-582X.2012.07.015
    [Abstract](1326) [HTML](0) [PDF 1010.50 K](844)
    Abstract:
    Dimethylphenylsilanol is easily refined into high pure silicon, but there is a lack of experimental data of its chemical bonding properties. The optimized molecular structure parameters of dimethylphenylsilanol are calculated through density functional theory (DFT) method with B3LYP/6 311++G** basis sets. Then, the molecular chemical bonding properties are investigated with the natural atomic obtain analysis, the frontier orbital analysis and the overlap population analysis under the natural bond orbital (NBO) theory. It is showed that the O-H bond isn’t affected when the phenyl and the methyl are joined into molecule, but the molecular energy and dipole moment are reduced, so as to make molecule more stable. The Si-C bond between silicon atom and the phenyl is weak. But the bond strength of Si-O is strengthened a little. The O-H bond is the weakest one in the molecular chemical bond. In addition, the electron on the carbon atom in the phenyl is prone to nonlocalizing primarily. The lone pair electron of oxygen atom transferring to the anti bonding orbital between silicon and carbon atoms weakens Si-C bond to some sort. So the gap of the theoretical principle of chemical bonding properties of C6H5(CH3)2SiOH can be filled and the basic theory of chemical reaction of C6H5(CH3)2SiOH is obtained.
    16  Numerical simulation on the seepage of tailings dam by centerline method construction
    WEI Zuoan CHEN Yulong LI Guangzhi
    2012, 35(7):89-93. DOI: 10.11835/j.issn.1000-582X.2012.07.016
    [Abstract](979) [HTML](0) [PDF 2.46 M](928)
    Abstract:
    Yangla copper mine is going to build a new tailings pond for its tailings disposal. The tailings dam is 185.0 m high and centerline method is used to construct the tailings pond. For the stability of the tailings dam, 2D FLOW program is used for the numerical simulation study about the dam seepage. During simulation calculation, different conditions which include a drainage system installed into the dam or not and different beach widths, i.e. 70 (the flood condition), 100, 300 m (the normal condition), are considered. Through calculation, the change of the seepage under different conditions is obtained, which shows if the drainage system is installed into the tailings dam, the underground water can be successfully drained out. This can keep the phreatic surface level relatively low, so as to improve the stability of the dam.
    17  Optimal calculation method of stabilizing force for anti slide piles
    WAN Ling WU Jian WEI Zuoan
    2012, 35(7):94-98. DOI: 10.11835/j.issn.1000-582X.2012.07.017
    [Abstract](935) [HTML](0) [PDF 1.36 M](861)
    Abstract:
    A new efficient method named matrix method is presented based on the traditional calculation methods of stabilizing force. The method is derived from the thrust force method and designed to address the deficiency of traditional method. It cannot only get the best pile location with minimum stabilizing force when is applied to the design calculation of single row anti slide piles, but also be applied to the optimal calculation of multi row anti slide piles. The cases comparing results show the method is more reasonable. For major projects of landslide control, the combination of matrix method and finite element method can make the result safer and more accurate.
    18  Energy analysis of concrete’s fracture expanding elements
    HUANG Yaoying ZHENG Hong
    2012, 35(7):99-106. DOI: 10.11835/j.issn.1000-582X.2012.07.018
    [Abstract](992) [HTML](0) [PDF 2.15 M](827)
    Abstract:
    Assume the material of concrete structure with crack is viscoelastic material, the relative displacement of crack side increases under load. If stress intensity factor is calculated by displacement direct method, the stress intensity factor will increase and may be even bigger than the concrete’s fracture toughness. The fracture problem of viscoelastic material is studied based on Entropy theory. It is showed that if the structure is viscoelastic material, there is no energy dissipation and release during the rheological process; the entropy is a constant and the crack remains stable, which means the displacement direct method is not feasible to rheological fracture problem. The blunt crack band model is preliminarily studied as well. It is believed that when fracture expanding element cracks, the structure energy will release, which is equal to the energy difference value between external work external work and total elastic energy and also approximately equal to the difference value between the total elastic energies of fracture expanding elements before and after cracking. As to linear elastic fracture problem, the stress intensity factor can be obtained by simply transforming the ratio of the energy difference value and virtual expanding length (plane problem) or virtual expanding area (spatial problem). It is also indicated by the analysis that blunt crack band model is independent of mesh size partly and its mesh can be obtained easier comparing with discrete crack model.
    19  Analysis on the relationship of interlayer and brine migration in salt cavern construction period
    CHEN Jie JIANG Deyi LIU Chun QIU Huafu DU Chao GUO Ping
    2012, 35(7):107-113. DOI: 10.11835/j.issn.1000-582X.2012.07.019
    [Abstract](1128) [HTML](0) [PDF 4.58 M](1035)
    Abstract:
    The interaction between interlayer and brine migration in cavity construction period is analyzed by taking the Jintan underground energy storage of salt rock in Jiangsu Province as a demonstration project and using RNG k〖XC半字线.tif,JZ〗ε turbulence model and material transfer theory. The study shows the movement of brine in the cavity construction process forms complex turbulences due to the affecting of interlayer. Vortexes are produced around the interlayer and their influence diminishes with the expansion of chamber. Additionally, the influence of the interlayer on flow field is also affected by washing techniques, such as water injection method, location of injection flow rate and spatial location of casing. At the same time, the non uniform flow of brine forms different degrees of water pressure on the interlayer. Generally, the interlayer is mainly affected by the water pressure generated by injection water flow in the former stage of cavity construction, while it is mainly affected by boundary mass flow in the latter stage of cavity construction. But in both stages, the pressure generated by brine flows is insufficient to make the interlayer collapse. PIV techniques are adopted to monitor migration law of the brine in physical model, and the law of brine movement in experiments is consistent with calculation results.
    20  Experiments on the relationship between permeability of gas bearing coal and coal body structure
    L Runsheng PENG Suping XU Yanyong
    2012, 35(7):114-118. DOI: 10.11835/j.issn.1000-582X.2012.07.020
    [Abstract](1058) [HTML](0) [PDF 1.52 M](876)
    Abstract:
    Permeability tests of type I to V coal from Jiaozuo coalfield are carried out to study the gas permeability difference of coals with different structures. The experimental results show that the relation curve of permeability to different coal structures show normal distribution, and the value of permeability first increases quickly and then decreases sharply. Type II coal’s permeability is the maximum and that of type V is the minimum. There is little difference of perm abilities of type I, type IV and type V. The concepts of variation coefficient of permeability and permeability ratio are brought in to evaluate the heterogeneity and anisotropy of No.21 coal seam. It found both of them are high, however, the homogeneity of a single type structure coal is good. Mechanisms of gas sub region and banding, gas emission, gas outburst of gas bearing coal are explained by the permeability differences. Permeability changes are the direct result of pore fracture development and the major controlling factor of gas distribution, gas emission and coal and gas outburst.
    21  Traditional mineral resource visualized dynamic estimation and its application in 3D geological space
    CHEN Guoxu ZHANG Xialin TIAN Yiping WU Chonglong
    2012, 35(7):119-126. DOI: 10.11835/j.issn.1000-582X.2012.07.021
    [Abstract](1291) [HTML](0) [PDF 4.76 M](963)
    Abstract:
    A new method for traditional mineral resource visualized dynamic estimation in 3D geological space is proposed, which is adaptive to the characteristics of resource exploitation and reserve classification in China. The method follows the daily workflow of mine exploitation, improves the traditional method for resource estimation by 3D visualization technologies, and replaces abstract regular geometries with real 3D geological models. Thus, the traditional method for resource estimation realizes visualization in the whole workflow of mine exploitation. The application results to some real mines show the estimation results are mainly affected by the spatial location, shape and thickness of mineral blocks and goaf. If the resource dynamic estimation is carried out by constructing 3D mineral models in consistent with real exploitation project, the accuracy of the traditional method can be effectively improved.
    22  Adsorption removal of 17α ethynylestradiol by wool fiber in the tertiary treatment of wastewater
    YANG Chun HU Bi bo Andrew Wheatley
    2012, 35(7):127-132. DOI: 10.11835/j.issn.1000-582X.2012.07.022
    [Abstract](1146) [HTML](0) [PDF 1.90 M](856)
    Abstract:
    17α ethynylestradiol (EE2) is the strongest estrogenic endocrine disrupting chemical, and it is hardly biodegradable. It can be removed by adsorption due to its hydrophobic property. The absorptive removal of EE2 is comparatively studied by pumping EE2 solution(5.0 μg/L) into upstream reactors, packed with granular activated carbon (GAC), manganese oxide (MnO2) and wool fiber respectively. The GAC reactor removes 99.8% EE2 without breakthrough, and the breakthrough in the MnO2 reactor happens after 8 days. Although the absorbability of wool fiber is higher than MnO2, the breakthrough in the wool fiber reactor happens after 12 hours. This lies in that the bulk density of wool fiber (10~20 kg/m3) is lower than that of MnO2 (1 900~2 000 kg/m3). A practically used wool fiber reactor may take more time to breakthrough due to the approximately three orders of magnitude lower EE2 concentration in the secondary effluent than that in these experiments, which is proved by the following pilot scale experiments.
    23  A real time monitoring method of energy consumption based on data mining
    QING Xiao xia XIAO Dan WANG Bo
    2012, 35(7):133-137. DOI: 10.11835/j.issn.1000-582X.2012.07.023
    [Abstract](1309) [HTML](0) [PDF 2.30 M](819)
    Abstract:
    A real time monitoring method of energy consumption based on data mining techniques is proposed to compensate the deficiency of common energy consumption methods in real time and intelligence. The new method can identify energy consumption patterns by clustering analysis of historical energy consumption data, get the decision tree of energy consumption pattern by classifying the energy consumption data, match the real time energy consumption data with the energy consumption patterns, make outlier analysis with historical data of the same pattern, and then determine whether the current energy consumption is abnormal. The experiment with energy consumption data from the comprehensive building proves that the new method is effective in detecting the abnormal data of energy consumption real timely.
    24  Experiments on the feature distribution and influencing factors of sediment phosphorus in a new artificial lake
    FAN Gongduan ZHANG Zhi REN Liping LUO Jing XIANG Ping YANG Dongxue
    2012, 35(7):138-144. DOI: 10.11835/j.issn.1000-582X.2012.07.024
    [Abstract](1354) [HTML](0) [PDF 2.68 M](904)
    Abstract:
    Experiments on the features distribution of sediment phosphorus is carried out with sequential extraction method in a new artificial lake. In addition, parameters affecting the sediment phosphorus, such as pH, temperature, dissolved oxygen and light, are examined. The experimental results show that inorganic phosphorus is the most component in total phosphorus, while active phosphorus is between 12.0% and 15.1%. The mass concentration distribution of the active phosphorus in descending order is as follows: slow flow area, lake outlet, lake centre, lake entrance, stagnation zone. Also, organic phosphorus in total phosphorus is in the range of 3.4% to 8.5% and its mass concentration distribution in descending order is listed as follows: lake outlet, lake centre, stagnation zone, slow flow area, lake entrance. At the same time, sediment phosphorus affected by the environmental factors is firstly released, followed by adsorption; increasing temperature and pH is beneficial to the release of sediment phosphorus; at lower dissolved oxygen, the release of sediment phosphorus is largely improved; and the release of phosphorus in the absence of light is significantly higher than that in the presence of light.

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