18 March 2011, Volume 29 Issue 11-08

    

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Articles
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  A Translocation Fluorescence Cross-correlation Tool for the Analysis of Protein-protein Interactions

  . 2011, 29(11-08): 22-26. https://doi.org/10.3981/j.issn.1000-7857.2011.08.001

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  Fluorescence proteins have become widely used molecular probes in the analysis of protein-protein interactions. There are many notable advantages, such as celerity, direct visualization, and noninvasive. Green Fluorescence Protein (GFP) from jelly fish and Red Fluorescence Protein (RFP) from coral are most important auto-fluorescent proteins in this field. A translocation fluorescence cross-correlation tool is developed base on the GFP and RFP for testing protein-protein interaction. To overcome the distract caused by non-specific spectrum permeation of two fluorescent proteins, the nucleolus localization signal sequence (NoLS) and nuclear export signal sequence (ABL signal sequences) are attached to both pairs of the system accordingly. Therefore, the proteins can express in and/or out of the nuclear which endues locomotion of protein pairs and their fluorescence tags. The dynamic protein-protein interaction of anti-apoptotic protein Bcl-2 and Bak-BH3 peptide is straightly and rapidly laid out in the translocation fluorescence cross-correlation tool.
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  Method of Reducing Thermal Mismatch Stress in Infrared FocalPlane Assembly

  LI Yanjin

  . 2011, 29(11-08): 27-30. https://doi.org/10.3981/j.issn.1000-7857.2011.08.002

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  Thermal mismatch stress in HgCdTe infrared focal plane assembly was studied by using the finite elements method. There will be tensile stresses in the HgCdTe/Si/Al2O3 three layers assembly under low temperature and damages would easily occur. According to the properties of expansion alloys, two configurations of infrared focal plane assembly are proposed to reduce the thermal mismatch stress effectively. One is that with the low expansion alloy invar layer below the Al2O3 piece, the other is that with constant expansion alloy kovar layer between the Si and Al2O3 pieces. 256×1 and 256×256 mid-wave HgCdTe infrared focal plane assemblies were prepared in these two configurations, respectively. The experiment results indicate that the reliability of HgCdTe infrared focal plane assembly is much improved.
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  Study of Superfine Melamine Fibers by Reaction Electrospinning

  . 2011, 29(11-08): 31-34. https://doi.org/10.3981/j.issn.1000-7857.2011.08.003

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  Melamine fibers were prepared by reaction electrospinning and their morphologies were observed by Scanning Electron Microscopy (SEM). The effects of various parameters on the diameter and morphology of the fibers were investigated, including viscosity of solution, tip-to-collector distance, voltage and conductance. The heat resistance of the electrospun mats was measured by Thermogravimetry (TG). It is shown that the average diameter of fibers d is related with the viscosity of solutions η and the voltages V, in the following manners: d∝η0.33 and d∝V-0.25; it increases then decreases with the increase of distance, and it decreases with the increase of conductance of solutions. The appropriate technical parameters of electrospinning of melamine fiber can be adopted as follows: the concentration of PVA is 8wt%, the applied voltage is 18kV, the distance is 12.5cm and the concentration of NaCl is 0.1wt%. The average diameter of the superfine fibers is about 400~600nm and the mats can thus be made with good heat resistance.
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  Chemical Equipment Failure Probability Model Based on JC Method

  . 2011, 29(11-08): 35-38. https://doi.org/10.3981/j.issn.1000-7857.2011.08.004

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  The chemical equipment general failure probability based on database statistics is the probability when the parameters of all failure modes take their respective mean. Risk Based Inspection (RBI) technology includes qualitative RBI judgment and quantitative RBI calculation. Through qualitative judgments, the relative level of risks can be obtained. The devices with relatively low risks do not need a quantitative RBI, and further quantitative RBI will be focused on those with relatively high risks. It is found that there are two important aspects in the use of pressure equipments in China, that is, severe defects and over-use, and it is proposed to control the risks. The shortcomings of the current API 581 method regarding to the severe defects and over-use are analyzed in this paper. With the reliability theory, the limitations of the mean first order second moment method are shown in practical applications as well as the shortcomings of RBI. In addition, the general failure probability of equipment based on JC model is calculated. This method can be used for any probability distribution and is not limited to the normal distribution. With the actual distribution of random variables being taken into consideration, this method can be used equally well for logarithm normal distribution, Weibull distribution or extreme value type I distribution. Besides, by means of equivalent normal deviation, the non-normal variable is transformed into a normal variable. The linearization point is not located at the mean value but the failure boundary, and is called the design check point, corresponding to the structural maximal failure probability, which can be used to estimate the failure consequence of equipment accurately.
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  Applications of Seismic Identification Technique to Low-levelFaults in Panhe Area

  . 2011, 29(11-08): 39-43. https://doi.org/10.3981/j.issn.1000-7857.2011.08.005

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  Panhe area is an oilfield with many low-level faults. Because of the complex fault system, the exploitation and exploration would become increasingly difficult, and it is important to identify correctly the low-level faults for the exploration of complex fault-block reservoirs. The well developed technology of collecting, processing and interpretating seismic data makes the 3D fine interpretation possible for low-level fault-block reservoirs. In this paper, an analysis of several exploitation seismic technologies is carried out from various angles to identify low-level faults, and the plane association matching technology of low-level fault is optimized. Then an explanation is made for the technologies of fine horizon calibration, horizontal slice, frequency-divided coherence, seismic forward modeling, as well as the well-controlled structure mapping technology. Panhe Area is taken as an example to apply these techniques to identify and recombine low-level faults. As a result, the distribution pattern of low-level faults in the area is obtained. In addition, the boundary of each fault block and oil-water system is identified, and the direction of exploration and regulation is made clear. The results show that these technologies can help petroleum exploration and development.
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  Numerical Simulation on Quasi-periodic Soil Temperature Field of Parallel Buried Pipelines

  . 2011, 29(11-08): 44-48. https://doi.org/10.3981/j.issn.1000-7875.2011.08.006

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  In the area of parallel buried pipelines, a temperature field of hot crude oil pipelines is influenced by the cool processed oil pipelines, therefore the temperature field of parallel pipelines is different from that of single pipeline. For hot crude oil pipeline, the soil temperature of hot crude oil pipeline is the base of shut down, start-up, and operation. It is necessary to acquaint the soil temperature in order to make sure the pipeline operate safely and avoid the pipeline condenser. Based on the soil properties measurement, the finite volume method is adopted to research the quasi-periodic soil temperature field around parallel buried pipelines by using quasi-periodic soil temperature field of parallel buried pipelines at Sipu inlet station of west pipeline as the example. The simulating data conform with the measured data，it is indicated that the mathematical model is correct and the results provide the reference for the engineering.
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  Domino Effect Caused by Pool Fire in Petroleum Storage Tank District

  . 2011, 29(11-08): 49-53. https://doi.org/10.3981/j.issn.1000-7857.2011.08.007

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  This paper presents a study of Domino effects, including the mechanism and characteristics. The Domino effect is a complex phenomenon, in which severe accidents may take place in chains. For example, in a petroleum storage tank, one accident may cause a secondary accident in other facility nearby. In this paper, the mathematical models of pool fire and the probability analysis are used for the assessment, including the vulnerability assessment of the consequence. The risk of the Domino effect is determined by using the quantitative risk analyses technique suggested in this paper. The probabilities of Domino events and their consequences are calculated. A systematic procedure for the quantitative assessment of risk caused by Domino effects is proposed for the risk analysis of petroleum storage pool fire accidents. The factors and the manners of the propagation and enhancement of the accident are analyzed by assessing the risk caused by Domino effect of pool fire. Safety measures to avoid Domino effect is thus suggested. This method can predict the secondary accident, the probability of the accident and the consequence. Therefore, the corresponding preventive measures can be taken so as to prevent Domino effect, reduce the probability of secondary disaster and enhance the inherent safety of the petroleum storage tank.
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  Open Pit Mining-stripping Sequence Optimization Based on 3D Simulation and Dynamic Evaluation

  . 2011, 29(11-08): 54-57. https://doi.org/10.3981/j.issn.1000-7857.2011.08.008

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  The disorder distribution of ore grade leads to different economic benefits caused by different stripping order. In order to obtain superior mine scheduling scheme, the paper proposed a mining sequence optimization method based on 3D simulation and dynamic assessment. By 3D simulation, the dynamic excavation of complex open mine under multi-level constraints was realized, and excavation quantity and grade of ore were obtained. According to mine general layout, stripping position and development, the calculation of transport distance, equipment selection, and infrastructure investment evaluation were carried out. And then combining the mineral advance price, the net present value of each scheme models was calculated. And finally the best optimization scheme through comparing NPV was determined. Take one molybdenum mine as example. First create a geological block model in the Surpac, and then assign the mine grade and value to the model, finally obtain series nest limit schemes by discounting price. According to the actual mining conditions, using MineSched software, the mining-stripping schemes were scheduled through various constraint means, and the optimal scheme was determined by applying the dynamic economic assessment.
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  Real-time Detection and Tracking of Road Information for Outdoor Vision-based Robot Based on Improved Otsu

  . 2011, 29(11-08): 58-62. https://doi.org/10.3981/j.issn.1000-7857.2011.08.009

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  The detection and tracking of road information are the basis and prerequisite of environmental exploration and autonomous navigation by mobile robot. In view of the complexity of the outdoor working environment of the robot and the variety of the outdoor illumination conditions, a suitable and novel way of real-time detection and tracking for outdoor robot is presented. First, the video images obtained from CCD camera are preprocessed. Then the Region of Interest (ROI) is extracted and transformed into the HSV color space. The edge information of the road image is obtained from the ROI by using the improved Otsu algorithm. With the anti-jamming ability of the Hough transform, the region where robot can pass through is shown. Finally the weighted Mahalanobis distance discrimination method is used to track the passing area. Experiment results show that this algorithm enjoys a good performance in the detection and tracking of road information in outdoor environment in real-time.
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  Detection System for Ultrahigh Vehicle Based on Laser Sensor

  . 2011, 29(11-08): 63-66. https://doi.org/10.3981/j.issn.1000-7857.2011.08.010

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  A detection system for ultrahigh vehicle is designed based on laser sensor. A laser screen is formed through emission sensors and receiving sensors, and the exact height of ultrahigh parts can be measured by judging whether the signals of the sensors are blocked. Optical modulation and optical demodulation are adopted for the design of hardware circuit in view of the interference of sunlight and strong light, to turn the laser signals into discrete signals. In this way, the problems of the interference of continuous light signals in nature can be solved effectively. In the software design, the Freescale MC9S12DG128 singlechip is used to control the emission signal and process the received signal, with a simple but very efficient program. Laser sensors are used in this detection system due to the strong anti-interference ability and the high accuracy to achieve dynamic measurement of vehicle height. The vehicle speed can be as high as 40km/h, and the system not only enjoys high measurement accuracy and high detection efficiency, but also can measure the height of hollow objects. In the actual detection experiment, the accuracy of the system can reach 5cm and, the detection range can be from 4m to 6m. The system is widely used in urban roads and highways to prevent large trucks from blocking in bridges or colliding with bridges.
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  Wind Tunnel Tests of MIRA Model Group for Study of Vehicle's Rear Shape

  . 2011, 29(11-08): 67-71. https://doi.org/10.3981/j.issn.1000-7857.2011.08.011

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  Automobile tail vortex is one of the main sources of vehicle's aerodynamic drag, and it is directly related to the shape of the rear vehicle body. MIRA standard model group was chosen in our study. Surface pressure measurement technique and Particle Image Velocimetry (PIV) technology were used in the wind tunnel tests to obtain the drag coefficient of the model group. The surface pressure distribution contour and the tail flow field on the longitudinal symmetry plane were obtained for qualitative and quantitative analyses of the model group and the relationship between the aerodynamic drag and the rear vehicle body shape is obtained. It is shown that: in the model group, the slope back model has the smallest resistance coefficient, the stepped back model has a slightly larger coefficient, and the straight back model has the largest; At the same time, in the tail negative pressure area, the distances between the tail vortex core and the vehicle body, and the tail vortex diffusion area see a tendency of increasing among these models.
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  SVM Parameter Selection Based on the Bound of Structure Risk

  . 2011, 29(11-08): 72-74. https://doi.org/10.3981/j.issn.1000-7857.2011.08.012

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  Support Vector Machine (SVM) is an intelligent technology for classification problems. Because of its flexibility, computational efficiency and capacity to handle high dimensional data, SVM has become a popular research issue in recent years. Selection of optimal parameters is important for an SVM. The traditional methods, such as the k-fold cross validation, can select optimal parameters, but would take too much time. In this paper, a method of SVM parameter selection based on the bound of structure risk is proposed. First, the bound of the structure risk is theoretically analyzed. Then, the simulated experiments with several datasets are designed. Comparisons are made between the proposed method and the method based on the 5-folds cross validation. The results show that the proposed method is effective and takes less time, and it would be very suitable for target recognition problems.
Reviews
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  Review on the Study of Particulate Emissions from Diesel Vehicle

  . 2011, 29(11-08): 75-79. https://doi.org/10.3981/j.issn.1000-7857.2011.08.013

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  Particulate Matter (PM) emission from diesel vehicle has important harm on environment and human health, which has been the focus of the researchers. The studies about the impacts of the important factors including engine driving cycle, ambient temperature and fuel quality on the PM emission from diesel vehicle, the sampling and testing method, physical characteristics of particles from diesel vehicle mainly related to the quality, physical form and particle size distribution, and chemical characteristics such as elements, EC/OC, inorganic ions and organic components of diesel particles were reviewed. Currently, composition spectrum of particulate matter from diesel need to be completed and update, sampling and analysis methods to be more accurately, the emission characteristics of particulate matter components need to be more studied.