18 December 2013, Volume 31 Issue 35

    

Articles
Reviews

• Select all
  |

Articles
• Select
  Integrated Design of Quasi-continuous High-order Sliding Mode Controller for Remote Guidance and Control System

  LEI Jia;MENG Xiuyun;LIU Zaozhen

  . 2013, 31(35): 15-18. https://doi.org/10.3981/j.issn.1000-7857.2013.35.001

  Abstract ( ) Download PDF ( ) HTML   Knowledge map   Save

  Longitudinal channel controller for the remote control guidance system by using three-point method is integrated designed, which is called quasi-continuous high-order sliding mode controller. Ideal quasi-continuous four-order sliding mode controller form was given, and differentiator was constructed in order to estimate higher differentiation of sliding mode surface. The high-order sliding mode control transfers high frequency switch control, and hides it in the process, so chatterings are avoided effectively. It is worth mentioning that it is a very effective method for uncertain model, because information about band is enough. Especially for systems with large parameter changes, nonlinear and time-varying, robus performance is shown.
• Select
  Analysis of Dynamic Responses of Junction of Connected Aisle and Tunnel Subjected to Train Vibrating Load

  SHI Chenghua;LIU Qiang;PENG Limin;YANG Weichao

  . 2013, 31(35): 19-23. https://doi.org/10.3981/j.issn.1000-7857.2013.35.002

  Abstract ( ) Download PDF ( ) HTML   Knowledge map   Save

  Based on effective stress analysis method, the main tunnel, connected aisle and formation interaction three-dimensional calculation model was proposed by finite difference program FLAC3D. On condition of single-time intersection of two trains, pore water pressure, deformation and principle stress of the typical section characteristic points of junction between the connected aisle and tunnel was emphatically analyzed. The results show that: under train vibration load, the closer the soil layer from the arch bottom, the larger the PPR, but all are smaller than 1, which still cannot reach the condition of liquefaction; the maximum displacement of lining appears at the arch bottom, of which the value is 0.16 mm; the maximum tension-compression stress of lining are all smaller than its design value of corresponding strength, which shows that the lining is safe under train vibration load.
• Select
  EEG Signals Classification Based on AR Model and SVM Algorithm

  HUANG Lu;LI Ran;GU Jun

  . 2013, 31(35): 24-27. https://doi.org/10.3981/j.issn.1000-7857.2013.35.003

  Abstract ( ) Download PDF ( ) HTML   Knowledge map   Save

  In P300 based brain-computer interface (BCI), the effective feature exaction and classification of P300 is the key to carry out the follow-up work. An electroencephalogram (EEG) classification method combining with autoregressive (AR) model and support vector machine (SVM) was proposed. For 10 channels EEG data, AR model was built up for each epoch. The estimation of AR coefficients was taken on using least square method and the estimated coefficient sequences constituted the feature vectors. SVM was used as classifier and dataset Ⅱ of BCI Competition Ⅲ was used to verify this method. The recognition accuracy arrived at 93.5% with 15 times stimulations. The experimental results and data analysis show that the method using SVM to classify the feature vectors composed of AR coefficient sequences owns satisfactory recognition accuracy. It lays good comparison theory and experimental basis for the realization of P300 based BCI.
• Select
  Breaking Interval Preferred Model Based on Uncertainty Measurement Theory

  YU Jian;ZHU Fei

  . 2013, 31(35): 28-32. https://doi.org/10.3981/j.issn.1000-7857.2013.35.004

  Abstract ( ) Download PDF ( ) HTML   Knowledge map   Save

  Different combinations of segment height, route spacing and breaking interval have a significant effect on the indicators of the depleted ore loss, thus affecting the mining economic benefits. In this paper, the uncertainty measurement theory and the AHP(Analytical Hierarchy Process) are used to establish an evaluation model of the unit concentrate earnings. The evaluation model takes account of various factors that affect the unit concentrate earnings, such as the dilution rate, the recovery rate, the grade of the rock mixed with waste rock and the grade of tailings. The measured data are used to create a single index unascertained measurement matrix, then calculate the weight of each index by the AHP and evaluate the unit concentrate earnings according to the credible degree recognition criteria, thus determine the preferred caving step. In examples, the unit concentrate earnings are optimal when the breaking interval is 4.8m for the 440 stratified of Dahongshan Iron, and the step for the optimal breaking interval is determined.
• Select
  Distribution of Reservoirs in Sequence Stratigraphic at the Upper Triassic Yanchang Formation at Qiaogouwan Area in Erdos

  PAN Yanghui;WEI Qinlian;WANG Bao;XIAO Ling

  . 2013, 31(35): 33-38. https://doi.org/10.3981/j.issn.1000-7857.2013.35.005

  Abstract ( ) Download PDF ( ) HTML   Knowledge map   Save

  The high-resolution sequence stratigraphic theories, and the methods of wavelet analysis and frequency spectral analysis were used to define the sequence stratigraphic framework of the Upper Triassic Yanchang Formation, which have five long base-level cycles and 21 to 25 middle base-level cycles. Based on studying the relationship between the sequence stratigraphic chronostratigraphic framework and reservoir development, it is found that the development and distribution of reservoir has been apparently controlled by the A/S and boundary of sequence stratigraphy of Yanchang Formation. Sandstone reservoirs with relatively good properties occurred mainly at the early stage of the ascending long base-level cycle and the late stage of the descending middle base-level cycle, especially at both sides of the interface of long-term base level cycle and middle-term level cycles. Sour fluids migrate along the interface, favoring the formation of induced porosity, which can improve the reservoir. Compared with traditional method, this method can eliminate the uncertainty of artificial division of sequence, improve precision and accuracy of cycle division and correlation, and improve the success rate of oil and gas exploration.
• Select
  Characteristic of Hydrodynamic and Its Relation to Distribution of Hydrocarbon in Palaeizoic Yulin Gas Pool

  SUN Mingliang;GUAN Hong

  . 2013, 31(35): 39-43. https://doi.org/10.3981/j.issn.1000-7857.2013.35.006

  Abstract ( ) Download PDF ( ) HTML   Knowledge map   Save

  Fluid potential is the key factor of distribution of hydrocarbon. The development of pressure in Upper Palaeizoic group in Yulin region was simulated by basin modeling technique. There are two recurrent processes of pressure development in Shanxi formation. The first occurred from middle Permian to early Jurassic, and the other took place from middle Jurassic to later Cretaceous. In later Triassic and early Cretaceous, there were two peaks of overpressure. The maximum value of overpressure surpassed 10 MPa. It took the same time as that of the hydrocarbon generation and the second peak of overpressure. From Paleogene to nowadays, gas diffusion decreased the coefficient of pressure from 1.4 to 0.8. Nowadays, the gas pool is located in the region of lower fluid potential in the period of hydrocarbon generation. It is suggested that paleo-fluid-potential controlled the distribution of hydrocarbon migration and accumulation in Yulin region.
• Select
  Numerical Analysis of Characteristics of Confined Wall-attached Jet Flow in Heading Face Excavation

  LUO Zhouquan;ZHANG Chaobo;LU Hao

  . 2013, 31(35): 44-47. https://doi.org/10.3981/j.issn.1000-7857.2013.35.007

  Abstract ( ) Download PDF ( ) HTML   Knowledge map   Save

  Research on excavation of rectangular heading face is conducted to understand the characteristics of air flow in the process of heading face excavation in underground metal mining with a forced ventilation system. The air flow field of forced ventilation in heading face excavation is a confined wall-attached jet flow limited by space, whose characteristics have great influence on ventilation of roadway. Problems such as dust and hazardous gases are tightly related to the characteristics of the jet flow. The jet flow in the excavation process of heading face working is a confined wall-attached jet flow, which is subject to limited space and makes it extremely difficult for the mine to effectively ventilate; the characteristics of jet flow are not fully consistent with those in the unlimited space. In order to improve the ventilation in heading face excavation of Fankou lead-zinc mine, a standard k-ε mathematical model of confined wall-attached flow field in the heading face excavation process is established and the boundary conditions of the model are determined. GAMBIT is employed for mesh generation, and the computational fluid dynamics (CFD) software FLUENT is selected to simulate the air flow field. The results are as follows. Firstly, the flow filed can be divided into 3 parts, that is, wall-attached jet area, impact jet area and backflow area; secondly, the initial length of the confined wall-attached jet is less than the value obtained by theoretic analysis; thirdly, the jet wall axial velocity is larger than that of the central inlet of the tube after the confined jet flow is fully attaching. The paper reveals the characteristics of the flow field, and is useful for the improvement of ventilation effect of confined wall-attached jet in heading face excavation.
• Select
  Two-stage Fuzzy Evaluation of Under-sea Stope Roof Stability Based on Rough Set Theory

  ZHAO Guoyan;YU Peipei;ZHOU Li

  . 2013, 31(35): 48-52. https://doi.org/10.3981/j.issn.1000-7857.2013.35.008

  Abstract ( ) Download PDF ( ) HTML   Knowledge map   Save

  In order to evaluate the stope stability scientifically and accurately, a two-stage fuzzy evaluation model of stope roof stability was established with the engineering practice of Sanshandao under-sea gold mining. Eleven indexes, i.e., compressive strength of rock mass, RQD, average joint spacing, groundwater condition, exposed area of roof, depth of stope, span of stope, span-depth ratio of stope, disturbance influence around, maximum exposure time of roof, support measures, were selected to be the evaluation indicators. Degree of membership of the continuous indicators was calculated using sectional-continuous functions and degree of the discrete indicators was obtained by fuzzy language variables. To avoid the influence of subjective factors, rough set theory was applied to determine the weight of indicators by training 12 sets of stope samples. Each of the 12 sets of stope samples was tested by the model, and the accurate ratio was 100%. Stability of another stope roof on the -400 m level was predicted by the model. The results show that the predicted stability classification was in good agreement with the actual situation. Therefore, the evaluation model can be used in the practical stope stability evaluation.
• Select
  Establish a Formula to Calculate the Displace Radius of CO₂ in Saline Aquifer

  WANG Tao

  . 2013, 31(35): 53-55. https://doi.org/10.3981/j.issn.1000-7857.2013.35.009

  Abstract ( ) Download PDF ( ) HTML   Knowledge map   Save

  Storage of carbon dioxide is one of the effective methods for utilizing greenhouse gas and reducing greenhouse gas discharge. The storage of CO₂ into saline aquifers is the best way to mitigate the green house effect. However, there is a risk of leaking during the injecting of CO₂ into saline aquifers. So it is necessary to calculate the displace radius of CO₂ in saline aquifer. Based on the Buckley-Leverett equation, a new formula is derived to calculate the displace radius of CO₂ in saline aquifer. The research results can provide a theoretic support and a field guide for calculating CO₂ storage volume and risk control in saline aquifer.
• Select
  Effects of Thermal Aging on Vibration Transmissibility of Expanded Polystyrene

  LI Chen;XIAO Shengling;LIU Ying

  . 2013, 31(35): 56-59. https://doi.org/10.3981/j.issn.1000-7857.2013.35.010

  Abstract ( ) Download PDF ( ) HTML   Knowledge map   Save

  Effects of thermal aging on the vibration transfer characteristics of expanded polystyrene (EPS) cushion material are studied. The purpose is to provide reference for the cushioning packaging design, and to ensure the protection in current process. The accelerated thermal aging conditions are simulated by the frequency sweep experiments to explore the change regularities of vibration transmissibility with the aging time. The results show that the vibration transmissibility was affected by many factors. Above all, the expanded polystyrene damping ratio rose as increasing the aging time and also the peak values of vibration transmissibility increased. It was found that the peak values of vibration transmissibility increased by 42.66% while load 5.0 kg and 21.96% while 2.5 kg by aging at 240h. Moreover, the transmissibility-frequency curve shift to the upper left with the load rising, and the transmissibility-frequency curve shift to the upper right as increasing the expanded polystyrene density. With due consideration of the analysis above, we may draw a conclusion that it's necessary to fully consider many factors such as the load, material density and thermal aging time, when choosing vibration-proof packaging materials.
• Select
  Construction of Lentivirus-mediated HPV16-E7 Gene RNAi Cell Model

  ABUDUKADEER Abida;HASIMU Axiangu;AINIWAER Saimire;ABULIZI Abudula;SHENG Lei

  . 2013, 31(35): 60-63. https://doi.org/10.3981/j.issn.1000-7857.2013.35.011

  Abstract ( ) Download PDF ( ) HTML   Knowledge map   Save

  The HPV16-E7 ggene RNAi cell model was constructed. A recombinant lentiviral siRNA expression vector was constructed using a HPV16-E7 oncogene specific siRNA fragment, and an RNAi cell model stably expressing the HPV16-E7-siRNA was established by transfection of 293FT virus-packiging cells with the viral vector followed by infection of HPV16-positive SiHa carcinoma cells with recombinant virus, antibiotica selection and molecular biological characterization. RNAi cell model was successfully established, stably transcribing the HPV16-E7-siRNA fragment, and the inhitory effect on target gene (E7) was also characterized by western blotting and RT-PCR. The RNAi cell model expressing the HPV16-E7 gene-specific siRNA fragment using lentiviral vector was stable, effective and feasible, which lays the foundation for the role study and carcinogenic mechanism of E7 protein.
• Select
  Copyright Management of Chinese Scientific Journal Article

  YAO Changqing;WU Xiaoxi

  . 2013, 31(35): 64-70. https://doi.org/10.3981/j.issn.1000-7857.2013.35.012

  Abstract ( ) Download PDF ( ) HTML   Knowledge map   Save

  Due to the disputes among the author, journal and information servicer caused by the ambiguity of copyright ownership in the copyright transfer and licensing agreements of scientific journal articles, the copyright management of Chinese scientific journal articles is studied and the copyright agreement including the format, type, property, content and other aspects of the transfer copyright and license agreement of Chinese scientific journal articles is also researched deeply. Meanwhile, the copyright agreements are developed for Chinese scientific journal article copyright transfer. It is pointed out that the management and development of scientific journal article copyright should adapt to digital development trend in order to avoid the dispute among the subject related with the copyright and ownership of scientific journal articles.
Reviews
• Select
  Emergency Preparedness for Small Modular Reactors

  QU Jingyuan;ZHANG Lin;HUANG Ting

  . 2013, 31(35): 71-75. https://doi.org/10.3981/j.issn.1000-7857.2013.35.013

  Abstract ( ) Download PDF ( ) HTML   Knowledge map   Save

  Small modular reactors (SMRs) have been an important international R&D activity because of their inherent safety features, modular construction approach and wide application perspectives. Compared with large scale nuclear power plants (e.g. 1000MWe light water reactor units), the economic performance of SMRs will be more sensible to outside constraints. It is especially the case for SMRs located in the very vicinity of the potential users. One of the possible constraints involves nuclear emergency preparedness and response. It would be very beneficial to the economic performance and the public acceptance towards SMRs if the plume emergency planning zones of them could be limited to their site boundaries. In fact, many concepts of SMRs have put this as one of their important design goals. Considering the factors in emergency planning, it would be currently not feasible to eliminate off-site emergency preparedness. However, it has been an international consensus that emergency planning could be simplified. For example, the emergency planning zones for SMRs may be significantly smaller than that for large scale light water nuclear power plants. This paper describes the current status of international R&D activities in the field of SMRs. The concepts and approaches governing the emergency planning in support of large light water reactors and SMRs are discussed. Relevant discussions and practice concerning simplification of emergency preparedness for SMRs are also briefly presented.
• Select
  Utilization and Development of Salt Caverns in the Field of Energy Underground Storage

  RAN Lina;WU Zhide;HAN Bingjie;

  . 2013, 31(35): 76-79. https://doi.org/10.3981/j.issn.1000-7857.2013.35.014

  Abstract ( ) Download PDF ( ) HTML   Knowledge map   Save

  With the low permeability,good creep and damage recovery of rock salt, salt cavern is a good medium of underground energy storage, and thus is used for gas, crude oil and liquid hydrocarbon storage. Salt cavern can also be used for compressed air energy storage and hydrogen storage, and storing and transforming surplus energy form renewable energy sources. At the same time, salt caverns are also widely used in the industrial waste, hazardous waste disposal, carbon dioxide sequestration and so on. This paper reviews the application of underground salt cavern in the field of energy underground storage and the basic principle, the technical development trend of salt caverns, and expounds the development status of China's energy storage in salt caverns.