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2013 Vol. 34, No. 6
Published: 2013-12-13
 
513 A Signal Processing Method for Frequencysweeping Interferometry
WANG Xuan-ze,ZHANG Shuai,ZHAI Zhong-sheng,YANG Lian-gen,LIU Wen-chao
DOI: 10.3969/j.issn.1000-1158.2013.06.01
A signal processing algorithm is designed for the absolute distance measurement system performed with frequency-sweeping interferometry. The system adopts frequency scanned method based on current modulation，and a comparing optical path and a measuring optical path are used to measure synchronously.The two interference signals are converted into electrical signals by two photodetectors and are used as input signals for absolute distance calculation.The principle of the measuring system and the characters of interference signals are presented，the difference smoothing convolution is used for processing the signals twice and the absolute distance is determined by the period or frequency information extracted from interference signals produced while scanning the laser frequency.The period calculating error of this algorithm is analyzed.The experiment results demonstrate that this method has major computing advantages.
2013 Vol. 34 (6): 513-518 [Abstract] ( 591 ) HTML (1 KB)  PDF (4599 KB)  ( 938 )
519 A Construction of Laser Interferometer of Nanometer Displacement Calibration System Based on HSPMI and Its Experiment Research
LI Qing-xian,GAO Si-tian,LI Wei,SHI Yu-shu,LU Ming-zhen,CHEN Ben-yong
DOI: 10.3969/j.issn.1000-1158.2013.06.02
A laser interferometer of nanometer displacement calibration system has been constructed based on high stability plane mirror interferometer (HSPMI).The layout of the calibration system is described.The data acquisition software based on VME bus has been designed for digital signal processing.Errors of the calibration system have been analyzed and the measurement accuracy is 293 nm.The results of the stability test and the nanometer displacement measurement of the calibration system demonstrate that the calibration system is effective and practical
2013 Vol. 34 (6): 519-523 [Abstract] ( 567 ) HTML (1 KB)  PDF (6202 KB)  ( 969 )
524 Image Reconstruction Algorithm for Electrical Capacitance Tomography Based on BP Neural Network
MA Min1,GAO Zhen-fu1,WANG Hua-xiang2
DOI: 10.3969/j.issn.1000-1158.2013.06.03
Considering the electrical capacitance tomography image reconstruction is an illposed problem, the system model is set up in COMSOL software, resolving the Forward problem. BP neural network is applied to realize the nonlinear mapping between the capacitance values and the reconstructed image grey values based on the nonlinear mapping and the association memory ability. Compared with the traditional ones, the algorithm avoids the trivial solution for the sensitivity matrix, and the linearization that reduces the imaging accuracy. Two filtering methods are proposed to improve image quality, and the simulation was completed in the MATLAB workbench.
2013 Vol. 34 (6): 524-528 [Abstract] ( 786 ) HTML (1 KB)  PDF (975 KB)  ( 1589 )
529 Investigation of the Influence of Vacuum on the Transmittance of Brewster Window
BAI Shan,LIN Yan-dong,LV Liang
DOI: 10.3969/j.issn.1000-1158.2013.06.04
The principle and process of the measurement are presented. The experimental results is analysed,the influence of vacuum on the transmittance of Brewster window is negligible compared with the uncertainty of optical power measurement and reproducibility of window transmittance measurement. The window transmittance measured in the air meet the requirement of cryogenic radiometer.
2013 Vol. 34 (6): 529-531 [Abstract] ( 566 ) HTML (1 KB)  PDF (282 KB)  ( 838 )
532 Deformation Resistance Model of Aluminum Alloy Based on Least Squares Support Vector Machine Reversed Modeling Method
YANG Jing-ming,MA Feng-yan,CHE Hai-jun,WANG Wan-hong,CHEN Yang
DOI: 10.3969/j.issn.1000-1158.2013.06.05
According to lots of actual measured rolling data of aluminum alloy from one factory of aluminum hot tandem rolling, the deformation resistance model by least squares support vector machine reversed modeling method is got.Meanwhile, Bacteria Foraging Optimization algorithm was applied to optimize the parameters of LSSVM model to improve the accuracy.Compared with the traditional deformation resistance model,the results show that the deformation resistance model by reverse modeling is more accurate.
2013 Vol. 34 (6): 532-536 [Abstract] ( 464 ) HTML (1 KB)  PDF (372 KB)  ( 1018 )
537 Study on Uncertainty of Volume Measerment by Hydrostatic Weighing Method and Production of Calibration Medium
GUO Li-gong,LIU Zi-yong,WANG Jin-tao,Tong Lin,Bao Xu-song
DOI: 10.3969/j.issn.1000-1158.2013.06.06
To propose that highpurity water which producted by microfilter,recerse osmosis and electrodeionzation technology is used as calibration medium and as a substitute for tapwaterTo correcte the density of water for factors as the water isotopic abundance，teperature gradient and dissolved air，the isotopic abundance，teperature gradient and atmosphere environmental parameters (t,p,RH) are measuredThe water quality report shows that the water be producted is in accord with the GB/T 11446.1 EW-I standardThe standard measurement uncertainty of water density is reduced to 7×10-3kg/m3,and the measurement uncertainty of the volume primary standard Urel is less than 3×10-5（k=3）.
2013 Vol. 34 (6): 537-540 [Abstract] ( 594 ) HTML (1 KB)  PDF (318 KB)  ( 890 )
541 Development of Metal Charpy V-notch Standard Specimen
CHEN Long,ZHANG Bao-zhu,HAN Chao,LUO Xin,PENG Tie-jun
DOI: 10.3969/j.issn.1000-1158.2013.06.07
The principle of development of metal Charpy V-notch standard specimen is described.Low energy grade and medium energy grade are produced from material of 40CrNiMo and tested using national benchmark impact tester.The results show that for low energy grade specimen, the average impact value is 24.836 J with the standard deviation is 1.4 J and stability during half year is 0.7%. For medium energy grade specimen, the average impact value is 97.514 J with the standard deviation is 3.0% and stability during half year is 0.8%.Both meet the requirements of national standard GB/T 18658-2002 and realize the transfer of impact energy reference value?Further the effects of process of development, microstructure and phase structure on impact energy value are analyzed.
2013 Vol. 34 (6): 541-544 [Abstract] ( 520 ) HTML (1 KB)  PDF (2093 KB)  ( 948 )
545 The New Development of International Comparison of Absolute Gravimeters
WU Shu-qing,LI Chun-Jian,SU Duo-wu,JI Wang-xi,XU Jin-yi
DOI: 10.3969/j.issn.1000-1158.2013.06.08
Global international comparison of absolute gravimeters activities had been held at BIPM(Bureau International des Poids et Meures)every four years since 1981.Recently,some changes had been taken place on this comparison activities.Meantime,regional international comparison of absolute gravimeters activities are rising in the world.The paper introduces the new development and some work in National Institute of Metrology.The result of NIM-II type absolute gravimeter which attended the 8th international comparison of absolute gravimeter in 2009 are also introduced.
2013 Vol. 34 (6): 545-547 [Abstract] ( 684 ) HTML (1 KB)  PDF (267 KB)  ( 841 )
548 Rolling Bearing Fault Diagnosis Based on Multiscale Entropy and Distance Evaluation
XIE Ping,JIANG Guo-qian,WU Xin,LI Xiao-li
DOI: 10.3969/j.issn.1000-1158.2013.06.09
In order to solve the difficulty in extracting nonlinear fault features, a new feature extraction method based on multiscale entropy and distance evaluation technique is proposed.First, multiscale entropy analysis is performed to extract and characterize detail features over different scales from bearing vibration signals.Second, distance evaluation approach is employed to evaluate the extracted features and select some sensitive features as subsets.The subsets are input into support vector machines for further condition classification and fault identification.Bearing fault diagnosis experiments validate the effectiveness of the proposed method.The experimental results demonstrate that the optimal sensitive feature subsets outperformed the single scale feature, the original feature sets and other random feature subsets in diagnosis accuracy.
2013 Vol. 34 (6): 548-553 [Abstract] ( 646 ) HTML (1 KB)  PDF (1619 KB)  ( 1252 )
554 Study and Implementation of Digital Drive Method for Coriolis Mass Flow Meter
HOU Qi-li,XU Ke-jun,FANG Min,XIONG Wen-jun,LIU Cui
DOI: 10.3969/j.issn.1000-1158.2013.06.10
The digital driving method which consists of frequency, phase and amplitude tracking based on DDS and MDAC is studied. A digital Coriolis mass flow transmitter is developed with TMS320F28335 chip. The driving technology is realized in real time. The gas-liquid two-phase flow-rate experiments are performed through connecting the transmitter with a CMF025 type Coriolis mass flow sensor. The results show that the transmitter can maintain the vibration of the flow tube and realize the flow measurement in two-phase condition.
2013 Vol. 34 (6): 554-560 [Abstract] ( 522 ) HTML (1 KB)  PDF (1207 KB)  ( 1306 )
561 Numerical Study of the Internal Flow Field in Three-channel Fuel Ultrasonic Flow-meter
TANG Jing-yuan,CHEN Jian-ming,WU Wei-long,TANG Guang-yu
DOI: 10.3969/j.issn.1000-1158.2013.06.11
For the circularsection bend pipe of the threechannel fuel ultrasonic flow meter, a computational fluid dynamic model is established on the basis of the incompressible Reynolds-averaged Navier-Stokes equations.The numerical simulation of the flow field characteristics in the pipeline is achieved by the renormalization group?k-ε?turbulence model, by applying the finite volume method and the structured grid for performing discretization, and standard wall function for modification in the near-wall region.The simulation results indicated that, under the eight kinds of different inlet velocity conditions, three channels velocity profiles are similarly not uniform and vary dramatically change along the axial direction of the pipe.The greatest change in the flow field characteristics is the H-H channel; the least change that is the P-P channel.The P-P channel has the best measurement accuracy and the H-H channel has the worst one.
2013 Vol. 34 (6): 561-566 [Abstract] ( 466 ) HTML (1 KB)  PDF (1903 KB)  ( 736 )
567 The Comparative Research on Wavelet and Hilbert Transform in the EEG De-noising
LUO Zhi-zeng,YUAN Fei-long,GAO Yun-yuan
DOI: 10.3969/j.issn.1000-1158.2013.06.12
To eliminate the noises mixed in the EEG effectively for completing the EEG analysis, a comparative research is made about the EEG de-noising effects of wavelet and Hilbert transform.In the HHT denoising method, using empirical mode decomposition algorithm to have 8 scales of decomposition for the EEG, and get the combination of components of intrinsic mode functions, then reconstruct the filtered signal, obtain the EEG after denoising finallyExperimental results show that HHT method can properly remove the noises which contained in the EEGThe denoising effects of HHT method and the wavelet transform method are compared by using the evaluation indexes.It finds that HHT method is better than the traditional wavelet transform in the EEG de-nosing and the efficiency of the HHT method is higher.
2013 Vol. 34 (6): 567-572 [Abstract] ( 784 ) HTML (1 KB)  PDF (1560 KB)  ( 1340 )
573 Effects of Dislocation of a Double Coaxial Coil on Magnetic Field
DONG Quan-lin1,2,3,LIU Xue-ping1,2,3,ZHANG Chun-xi1,2,3,YAO Jun-en3
DOI: 10.3969/j.issn.1000-1158.2013.06.13
The magnetic field distribution varies with the dislocation of coaxial drive coils. The basic Biot-Savart law and the superposition theorem is applied to work out the calculation formulas of the magnetic field, and with the help of MATLAB the numerical solution of the variation magnetic induction is calculated and the field plots is drawn. Based on these, the effects of the coil winding rules on the magnetic field distribution were judged and reasonable theory suggests is given about the magnetic field incentive and maintenance calculation results show that the effect of dislocation of a double coaxial coil on magnetic field is less than the order of 10-6 that is acceptable to actual application currently.
2013 Vol. 34 (6): 573-578 [Abstract] ( 684 ) HTML (1 KB)  PDF (1089 KB)  ( 1136 )
579 Defect Recognition of Metal Magnetic Memory Testing Based on Improved Fuzzy Support Vector Machine
ZHU Hong-yun,WANG Chang-long,WANG Jian-bin,LIU Bing
DOI: 10.3969/j.issn.1000-1158.2013.06.14
Since the metal magnetic memory (MMM) signal is weak and the defects can’t be recognized effectively, a novel fuzzy support vector machine(FSVM) is proposed. In order to reduce the influence of isolation point and noise on classification accuracy, the?k?nearest neighbor dispersion is constructed based on the traditional determination method of the fuzzy membership. Besides, the feature weighted degree of each feature is calculated to reduce the influence of redundant and weak features on classification accuracy. And then the proposed approach is applied to recognize MMM signals of different areas, the experimental results show that the proposed approach can recognize this MMM signals effectively，it is more robust and has the better performance of recognition. The proposed FSVM approach is a feasible recognition algorithm for MMM signals of different areas.
2013 Vol. 34 (6): 579-582 [Abstract] ( 519 ) HTML (1 KB)  PDF (318 KB)  ( 932 )
583 Testing Techniques for Diagnosis of a Hydrogen Maser
YANG Hao,CAI Yong,ZHANG Wei-qun,ZHAI Zao-cheng
DOI: 10.3969/j.issn.1000-1158.2013.06.15
To describe testing techniques for a hydrogen maser,these techniques are important for operating point setting and optimal operating condition keeping as well as for understanding and calculating of long-term frequency behavior of a hydrogen maser during its operation, especially long period of operation.The methods which are for producing and processing of a maser “baseline” data are also presented.
2013 Vol. 34 (6): 583-586 [Abstract] ( 531 ) HTML (1 KB)  PDF (2472 KB)  ( 779 )
587 The Compensation Method of the Supported Bilayer Lipid Membrane  Electrode Temperature
LV Ying-chun,QIN Jian-min,LV Qing
DOI: 10.3969/j.issn.1000-1158.2013.06.16
An electrode process temperature compensation method of supported bilayer lipid membrane(S-BLM) conductance is proposed.By S-BLM conductance sensor test system, the relationship between S-BLM conductance and temperature is studied.Under the premise of linear hypothesis, using the least square parameter estimation method,the S-BLM conductance sensor's characteristic curve linear equations between slope, intercept and temperatures are derived,then according to characteristics of the sensor curves get S-BLM electrode process temperature compensation model and provide realization method using LabVIEW.Based on effect test of the linear hypothesis and accuracy analysis,and through actual test, the validity and practicability of the proposed method is confirmed.
2013 Vol. 34 (6): 587-591 [Abstract] ( 541 ) HTML (1 KB)  PDF (1221 KB)  ( 858 )
592 Study on the Reference Calorimeter and Method for Determining Calorific Value of Natural Gas Based on Oxygen Bomb Calorimeter
LI Jia,SUN Guo-hua, WANG Hai-feng,MENG Fan-min
DOI: 10.3969/j.issn.1000-1158.2013.06.17
According to the research status and application requirements for energy measurement, the reference calorimeter of natural gas is studied.The calorific value of high-purity methane is determined by the oxygen bomb calorimeter, an adiabatic oxygen bomb calorimeter calibrated by the CRM of benzoic, which calorific value of the benzoic CRM traces to SI unit via the national standard.The device sample collect and equilibrium designed by NIM is described.The superior calorific value of methane is 39 900 J/m3 with an expanded rative uncertainty of (the expanded factor,0.6% k=2）.
2013 Vol. 34 (6): 592-596 [Abstract] ( 856 ) HTML (1 KB)  PDF (940 KB)  ( 2140 )
597 Research on Transgenic Cotton Mon15985 Plasmid Reference Material and Uncertainty Analysis
ZHANG Ling,SHENG Ling-hui,WANG Jing,LIU Fang-fang,LI Liang,MI Wei,DONG Lian-hua
DOI: 10.3969/j.issn.1000-1158.2013.06.18
Method validation is researched on transgenic cotton Mon15985 quantitative realtime PCRA multilaboratory validation experiment is carriedThrough statistical analysis, the reference value of Mon15985 plasmid reference material is 1.02, with expanded uncertainty of 0.04(k=2)?Comparing plasmid molecules and transgenic cotton Mon15985 genomic DNA, both slope and linear correlation of the expansion curve are replaceableTherefore, the transgenic cotton Mon15985 plasmid reference material can be used as analytical testing standards in relevant transgene detection experiments.
2013 Vol. 34 (6): 597-601 [Abstract] ( 559 ) HTML (1 KB)  PDF (330 KB)  ( 788 )
602 NOx Emission Characteristic Model for Circulating Fluidized Bed Boilers Based on GSA-SVM
NIU Pei-feng,MA Hong-bo,LI Guo-qiang,MA Yun-fei,CHEN Gui-lin,ZHANG Xian-chen
DOI: 10.3969/j.issn.1000-1158.2013.06.19
In order to accurately predict the NOx emissions of circulating fluidized bed boiler,a GSA-SVM model based on support vector machine (SVM) of NOx emission was established on the base of the sample data of circulating fluidized bed boilers in a power plant.The gravitation search algorithm (GSA) was applied to the process of the model parameters optimization because the accuracy and generalization ability of SVM model depended on the parameters.The prediction performance of the model was tested by sample datas under different experimental conditions.The regression model was compared with BP and the SVM model whose parameters were optomizated by particle swarm optimization(PSO) and genetic algorithms(GA). Finally the simulation result shows that the GSA-SVM model has a good recognition ability and generalization ability
2013 Vol. 34 (6): 602-606 [Abstract] ( 772 ) HTML (1 KB)  PDF (797 KB)  ( 1062 )
607 Development of  SO2F2 Gas Reference Material for Monitoring the Protecting Gas in Electrical Equipments
YAO Qiang,WANG De-fa,GAI Liang-jing,MIAO Yu-long,WU Hai,QIU Ni
DOI: 10.3969/j.issn.1000-1158.2013.06.20
The development of SO2F2 in helium gas reference material in cylinder is reported.The standard reference gas mixture is prepared by filling SO2F2 pure gas and high purity He into a cylinder.The influences of gas pressure in cylinder and the time of storage to the stability of the gas mixture are studied.The homogeneity of gas mixtures is also checked as while as the uncertainty evaluation from it.The results show that the homogeneity is good for each concentration level.The uncertainty from gravimetric method and stability are also evaluated.The relative extended uncertainty of SO2F2 reference material made by gravimetric method is not bigger than 2%,with good stability within six months.
2013 Vol. 34 (6): 607-610 [Abstract] ( 593 ) HTML (1 KB)  PDF (545 KB)  ( 1092 )
611 The Application of Double-error Regression in Uncertainty Evaluation Method for Sulfate Determination by Ion Chromatography
YU Jian-guo,ZHOU Xiao-hong,WANG Hua,DENG Zhen-ping
DOI: 10.3969/j.issn.1000-1158.2013.06.21
An uncertainty evaluation method for sulfate determination in karst underground water by ion chromatography detection technology is proposed.Using continuous propagation model of uncertainty,the sulfate measurement uncertainty is evaluated.The main sources of measurement uncertainty come from sub-uncertainties of calibration solutions,calibration curve fitting and measurements process.The double-error regression is used in the process of standard curve fitting.Based on the quantitative analysis of each uncertainty component during experimental results,the standard uncertainty model for sulfate determination results is obtained.
2013 Vol. 34 (6): 611-616 [Abstract] ( 530 ) HTML (1 KB)  PDF (401 KB)  ( 1011 )
617 Key Comparison CCQM-K32 for Thickness Measurement of Ultrathin Silicon Oxides on Silicon Wafer
WANG Hai,LIU Fen,KAN Ying,SONG Xiao-ping,ZHAO Liang-zhong,QIU Li-mei
DOI: 10.3969/j.issn.1000-1158.2013.06.22
Based on X-ray photoelectron spectroscopy technique, the National Institute of Metrology (NIM) of China developed an accurate analytical method and participated in the CCQM-32 international key comparison on thickness (less than 10 nm) measurement of ultrathin silicon oxides on silicon wafer.According to the published results of CCQM-K32, the NIM results with the expanded uncertainty of 4.6％～7.0% are agreed with the key comparison reference values and the degree of equivalence is gained.
2013 Vol. 34 (6): 617-622 [Abstract] ( 513 ) HTML (1 KB)  PDF (1509 KB)  ( 970 )
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