28 May 2014, Volume 32 Issue 15

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  • CAO Yan, DUAN Jin'ao, GUO Jianming, GUO Sheng
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    The analysis and evaluation of inorganic elements in Sargassum pallidum and Sargassum fusiforme from different regions provide may theoretical evidences for formulating harmful elements limit standards and comprehensive utilization of sargassum. The contents of 30 inorganic elements in Sargassum from different regions were determined by ICP- AES and iodine ion- selective electrode after ashing and digestion. Principal component analysis was carried out to evaluate Sargassum samples. The results showed that Sargassum from different regions contain 19~26 inorganic elements, with the average contents K>Ca>Na>Mg. The mean values of Cu, Hg, Pb, Cd, As and Al are 7.83, 1.54, 3.07, 3.02, 109.35, and 1434.26 mg/kg, respectively. No significant difference between S. pallidum and S. fusiforme was found in most elements. Principal component comprehensive scoring showed Samples H4 and H3 of S. pallidum from Yantai and Samples Y5 and Y6 of S. fusiforme from Wenzhou are the top four, indicating that these regions have better S. pallidum and S. fusiforme in terms of inorganic elements.
  • YI Lina, CUI Qingfeng, MA Yuandong, YU Li, HUANG Lixin
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    A group of nutrient activators with respect to injection well LU3064 in Xinjiang oil field Hutubi river group are designed, for emulsifying the crude oil. With the bacteria counting method, the MPN method, and the physiochemical property detection method, it is discovered that, in the injection water, upon activation, the concentration of bacteria rises significantly, while its surface tension decreases by 37%. With the molecular biological techniques (16S rDNA clone library), the LU3064 injection water, the LU3036 produced water and the LU3064 activated water are studied. One hundred clones are randomly selected from the clone library to blast in Genbank. The observations show that the injection water is highly diversified, and Alphaproteobacteria is the dominating bacteria. Compared to the injection water, the produced water has a simpler structure, which provides habitats with function bacteria genera such as Pseudomonas, Bacillus, etc. The community structure is found most monotonous in the activation fluid, only Bacillus can be found. Bacillus is discovered in both the injection water and the produced water, but does not dominate in them. The formula successfully activates Bacillus which can be grown in the stratum.
  • FENG Lijie, FAN Yao
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    The traditional target recognition based on multi-sensor environment has two methods. On the one hand, the data obtained from the multi-sensor are used for data fusion, on the other hand the signal obtained from each sensor is used for feature fusion. The two methods both have the problem that the target recognition accuracy is not high. In order to solve this problem, this paper presents a fusion method based on D-S evidence theory. On the basis of a multi-sensor target recognition system model, D-S evidence theory is used for data fusion based on the multi-feature information of a single sensor. According to the sensor signal-noise ratios of the received signal the credibility is determined, which is taken as the weight of evidence of the weighted combination of D-S evidence theory rule to complete the target recognition. This method considers many characteristics information of the sensor and the reliability of the sensor, overcomes the defect that evidence conflict management ability is limited by the traditional D-S evidence theory. Experimental results show the correctness and validity of this method, as well as the improved accuracy of target recognition.
  • CHEN Yuqiang, SU Jian, ZHANG Lei, YANG Guozhen
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    As a signal transfer hub, switch matrix plays an extremely important role in the automatic test equipment (ATE). When the distance between the source node and destination node is the shortest, signals can be transmitted in a most efficient way. First, a physical model of switch matrix is presented. Then a mathematical model is constructed by using graph theory. In view of the least relay and highest reliability, the problem is considered as a shortest path search in un-weighted graph and weighted graph. These two graphs arestudied by BFS algorithm and Dijkstra algorithm, and the improvedalgorithm is put forward. An actual example shows how to build the model and find the optimum path. The improved algorithm could realize rapid automatic searchfor the optimum path, thus has potential applicationsin development of general adapters and design of software platform in ATE.
  • LU Junyan, QIN Li, LI Yanan
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    The galloping of a quad- bundled conductor seriously threats the safe operation of the issue of EHV lines, and a theoretical study of galloping can effectively help the development of anti-dance techniques. A two-node cable element with three translational and one torsional degrees of freedom at each node is utilized to imitate the bundled conductor, and a two-node space beam elements are used to simulate the spacers, thus to establish the galloping finite element analysis model with considerations of the sub- conductor wake interference. The finite element equation is solved by the time integration method and the calculation program is compiled in Matlab. The central difference method is used to deal with the acceleration and the velocity is handled by the backward difference method. Typical examples of the galloping are simulated. With numerical simulations, the dancing in consideration of the effect of the sub-conductor wake is compared with that without. It is shown that this method can effectively simulate the galloping of ice quad-bundled conductors, the algorithms enjoy high accuracy and efficiency, and can be used in the design to prevent the dancing.
  • WEI Lianyu, LIU Yanzhu, MA Shibin, WANG Qingzhou
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    Application of the explosive compaction technology is proposed to solve the problem that conventional high-filled embankment reinforcementproject is costlyand has unsatisfactory effect.,A cavity is formed after blasting in soilunderground,withthe soil around the cavitycompressed under blast loading.The embankment is reinforcedby filling materials into the blasting cavity and compressingthem layer by layer. This paper studies the explosive experiments under nine different conditions and analyzesthe compaction effectunder different water content and compaction degree. The results show thatsoil with lowcompactiondegree and highwatercontent before blastingformsblasting cavities with relatively large radius.The test project carried out on a highwaywith highfilled embankmentdemonstrated that application of thetechnology achieved satisfactory effect with undamagedpavement and slope, shortened duration of maintenance and repair,reduced cost,and reduced impact of road construction on traffic.
  • LI Chunjia, SHEN Mengfei
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    With the fully mechanized coal mine surface of a mine 210108 as the object of research, in view of the fact that the working face is hard and the natural caving roof is not easy to colapse, in order to determine its characteristics under the condition of the mine, an observation scheme is devised for the thick sand roof under the condition of the deep hole blasting weakening the mineral pressure. Based on the measured data and the daily field pressure analysis, the pressure characteristics, the stope roof activity and the abutment pressure distribution are studied, and analyzed during the first weighting and periodic changes of the support load. It is shown that under the condition of hard roof weakening, an understanding of the mine pressure variation law is of great significance to safety and efficiency of the working face mining.
  • YU Shujiang, YANG Chengyi, XU Jiyuan
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    A coal mine might become a complex ventilation network to influence the stability and the reliability of the mine ventilation system when some large air-leakages exist in the underground coal mine. If the air leakage passage is connected with a fire area, the very serious results will be brought about. The air leakage of the 9211 airway in the Beizu mine shaft is measured by using the method of the continuous and quantitative releasing of SF6, and the air flow leaking into the 9211 air way can quantitatively determined. The amount of the air leakage is calculated by determining the shortest distance of the detection, the detection time, the release volume and other air leakage determination parameters, according to the change of the concentration of SF6 gas. Two air leakage areas in the 9211 air way are detected, to provide a foundation to take corresponding measures of prevention and control of the mine air leakage, and the technical support to the mine fire prevention.
  • SUN Li, LI Jiange, HAO Shengyue, ZHOU Qinghua, JIANG Baoyi
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    The main controlling factors on reservoir's physical properties are the bottleneck in the oilfield development in Baiyingchagan Sag. With respect to the Tengger formation, the major reservoir in the lower cretaceous system, on the basis of the related theory and the method of the reservoir geology, by using core logging, well logging and testing data, the petrological characteristics, the pore types, the pore structure and the physical characteristics are studied, and its main controlling factors are revealed. It is indicated that the reservoir physical properties are obviously controlled by the distribution of sedimentary facies, especially, the microfacies, the high quality reservoirs would distribute along the debouch bar microfacies, the underwater distributary channel microfacies, the sand dam within the fan-delta front and the braided river delta front. Moreover, the diagenetic reformation is the secondary controlling factor for the reservoir physical property of Tengger formation, among which the compaction has an obvious effect to cause a poor physical property, the cementation is responsible for the dualism effect, and the dissolution plays a constructive role. Finally, it is revealed that the high quality reservoir distribution and the favorable sedimentary facies belt distribution are closely related with each other.
  • LUO Litao, XIAO Hanmin, LIU Weidong, SUN Linghui, LI Jiye, GOU Feifei
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    The suspended particles in a reinjection sewage might plug the reservoir and reduce the permeability. This makes it difficult for the Ansai low permeable oil field to inject water and produce oil at present. In order to improve the effect of water flooding, a reasonable index of suspended particles for Ansai oil field has to be determined. For this purpose, five different particle sizes are considered with three different suspended particle concentrations in the Ansai natural core flow experiment. The results show that the permeability of the cores is reduced slowly with the increase of the injection of the suspended particles. When the injection reaches a certain amount, the permeability tends to be a stable value for a long time. When the concentration ρ>2 mg/L, the permeability is reduced more than 30%; when ρ≤1.0 mg/L and the particle size d<0.730 μm, the permeability is reduced less than 30%; when 1.0 mg/L<ρ< 2.0 mg/L and d<0.730 μm, the two factors act together, the permeability may be reduced more or less than 30%; when 0.730 μm≤d≤ 2.100 μm, the permeability is reduced more than 30%. It is therefore suggested that the range of the suspended particle size should be limited and stay away from the throat size of the reservoir in the water injection process. ρ<1.0 mg/L and d<0.730 μm for the Ansai low permeable oil field.
  • Reviews
  • KONG Chao, LI Dan, CHEN Zuojia, PICCION Miranda, YUAN Xiaojun, LI Bin
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    FOXP3+CD4+CD25+ regulatory T cells(FOXP3+Tregs)belong to a specific subset of CD4+ T cells which modulate many immune responses and play an indispensable role in maintaining immune homeostasis in vivo. Many major human diseases such as the autoimmune disease, the infectious disease, the allergic disease, the transplanting rejection and the cancers are associated with the dysfunction of the Tregs. The forkhead family transcription factor FOXP3 is a master regulator in the development and functions of the Tregs. Recently, a common conclusion is shared by many reseachers that the FOXP3 is not a solo transcription factor, it interacts with some other transcription factors such as the STAT3 and the RORγt to form a complex, to dynamically modulate the specific gene transcription progress. Furthermore, many studies including those of our laboratory demonstrate that posttranslational modification of the FOXP3 also plays an important role in the functions of the Tregs. In summary, further understanding of molecular mechanisms underlying the regulation of the FOXP3+Treg function by inflammation will lead a novel therapeutic clue for conquering major human diseases.
  • ZHANG Guangsheng, LI Changchun
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    An information support can be provided for the mine environmental recovery and management by monitoring and evaluation of the opencast mine area vegetation damage. This paper reviews the methodologies concerning the vegetation damage monitoring and evaluation in opencast mine area. The studies in China cover two main aspects: the surface coverage information extraction based on the remote sensing technology and the analysis of damaged vegetation spectral characteristics, focusing on vegetation physiological and biochemical parameters for monitoring the mining area of vegetation; the studies abroad include three aspects: the mining area vegetation monitoring for microscopic and macroscopic vegetation damages, the spectral characteristics and the calculation of the vegetation damaged vegetation index. The future work on the problems of mining area and vegetation monitoring is discussed.