18 August 2011, Volume 29 Issue 23

    

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  Study on Plant Community Characteristics and Species Diversity of Riparian Zone Along Taizi River

  LI Yue;MA Xiping;LI Fayun;HOU Wei;YANG Chunlu;CHENG Zhihui

  . 2011, 29(23): 23-28. https://doi.org/10.3981/j.issn.1000-7857.2011.23.001

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  The species diversity is an important trait of plant ecological adaptive strategy. The plant community of riparian zone along Taizi River plays an important role in the stabilization of plant composite. However, the species diversity of riparian zone along Taizi River is quite poorly known. The objectives are to investigate the species diversity of the understory of riparian zone along Taizi River in order to provide the theory of ecological restoration and technical basis. The diversity of plant species in 23 plots of the zone is investigated by calculating the indices of species diversity, richness, evenness, and dominance from important values. The results indicate that there are 201 species of plants belonging to 36 families and 124 genera in the 23 plots of riparian zone along Taizi River. The species composition of the community is relatively rich, but all are confined to herbaceous plant. The main families are dominated by the Compositae, Gramineae, Polygonaceae, Cyperaceae, and Rosaceae. The compositions of the community are concentrated, and the plant species give first place to Juncus effusus L., Beckmannia syzigachne (Steud.) Fern., Polygonum hydropiper L. angustifolium A. Br., Echinochloa crusgalli (L.) Beauv., Alopecurus aequalis Sobol., Polygonum hydropiper L., Rumex acetosa L., Artemisia adamsii Bess., Carex dispalata Boott ex A. Gray, Zoysia sinica Hance, Poa subfastigiata Trin., Scirpus orientalis Ohwi, etc. The community structure of riparian zone along Taizi River is simple in studied area. The ecosystem is deteriorating with richness indexes changing between 3.00—28.00, Pielou indexes changing between 0.66—0.89, Simpson indexes changing between 0.54—0.91, Shannon-wiener indexes changing between 0.86—2.73, Simpson dominance indexes changing between 0.09—0.46. The riparian zone along Taizi River is disturbed by human activities, such as agricultural production, dredging, and other human activities that result in the reduction of the level of community diversity.
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  Sino-atrial Node Cell Dissociation Method and Pacemaker Current Characteristics in Rabbits

  WANG Teng;WU Pingya;FAN Xinrong;CHEN Yongjun;CHEN Hui;HUANG Congxin

  . 2011, 29(23): 29-32. https://doi.org/10.3981/j.issn.1000-7857.2011.23.002

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  The isolation means and properties of morphology and pacemaker current I_f in Sino-Atrial Node (SAN) cells of rabbits are investigated. In the present study, the SAN trip containing "the central nodal region" is located by tagging super vena cava with black fine tread as a mark in right atrium of rabbit. The beating pacemaker cell of the SAN is spontaneously isolated by two dI_fferent enzymatic digestions. Hyperpolarization-activated pacemaker current is recorded by using whole-cell perforated patch technique in SAN cells. The results show that SAN tissue which include the "central nodal region" is shaped with superior wide and inferior narrow, and with an volume size that is approximately 6.25mm×2.23mm×0.26mm or 6mm×2mm×0.1mm—6mm×2mm×3.3mm. SAN cells are long thin spindle-shaped with faint cross-striations. They are measured with (65.3±7.8)μm in length and (7.2±3.1)μm in width. In normal Tyrode's solution, the typical SAN cells which are 2%—5% in yielded all of them are recovered spontaneous beating with frequency of (187.3±5.6) times/min. According to voltage clamp protocol, I_f is elicited as the inward ramp current, and becomes larger as soon as is activated more rapidly with the increasingly negative potential. The tail current of I_f has similar characteristics in same conditions. The current-voltage curve of I_f and tail is appearing as a typical horizontal "Y" according to their current density and clamp potential. It could be identI_fied that the isolated SAN cells have typical morphological properties and activity, therefore could be completely elicited inward ramp I_f, the fact could contribute to the dI_fferent investigations on I_f in SAN cells in cardiovascular areas.
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  Effect of Rosuvastatin on Endothelial Dysfunction of Rats Caused by Hyperuricemia

  XILIFU Dilidaer;ABUDULA Abulizi;ZHAO Ping;SONG Lijuan;REHEMU Nijiati;ZHANG Xiangyang

  . 2011, 29(23): 33-38. https://doi.org/10.3981/j.issn.1000-7857.2011.23.003

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  To study the effect of rosuvastatin on hyperuricemia rats and their endothelial dysfunction. 72 male SD rats were randomly grouped, and a hyperuricemia animal model was established by intraperitoneal injection of yeast extract and oxonic acid potassium salt. By setting up the treatment with allopurinol as positive control, the hyperuricemia rats were treated with various doses of rosuvastatin, the levels of Uric Acid (UA), Nitric Oxide (NO), Endothelin 1 (ET-1) and Angiotensin II (Ang II) were detected in serum using commercially available detection kits and the protein expression level of endothelial NO synthase (eNOS) was detected in tissue specimens of aorta by immunohistochemistry. The results show that, compared to the normal control, the serum levels of UA, ET-1 and Ang II of hyperuricemia rats are increased while the serum level of NO and the eNOS expression in tissue specimens of aorta, as an important profile for altered endothelial function of the experimental animal model are decreased. After treatment of the animal model with rosuvastatin, it is found that the drug has improved the profile of endothelial function, which has gradually recovered to the normal level, and the curative effect is significantly higher than the allopurinol group (positive control) at the dosage of 10mg/(kg·d) and intervention time of 6 weeks, as compared to the normal control group, with significant differences from the animal model without treatment. The results suggest that the rosuvastatin treatment can improve the profile of endothelial function via recovering the serum levels of ET-1, Ang II and NO, eNOS induced by hyperuricemia, and the effect is enhanced in a dose-dependent manner.
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  Hydrocarbon Accumulation Model of Silurian Strata of Oil-gas Reservoir in Tazhong Area, Tarim Basin

  DUAN Zhongyu;PANG Hong;PU Qingshan;MA Yongqin

  . 2011, 29(23): 39-44. https://doi.org/10.3981/j.issn.1000-7857.2011.23.004

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  There are a lot of asphaltic sandstones that is widely distributed in Tazhong Area, Tarim Basin; however the condition of hydrocarbon accumulation is complex. It is of great practical significance to study the hydrocarbon accumulation model of Silurian strata in order to accelerate the process of oil and gas exploration in the Tazhong Area. The distribution and genesis mechanism of asphaltic sandstones and movable oil of Silurian have been analyzed, and the hydrocarbon accumulation model have further been summarized. The results show that (1) the movable oil of Silurian strata in Tazhong Area is from the mixed-source rocks of the Cambrian and Ordovician; there are two stages of hydrocarbon accumulation, that is, Hercynian and late Himalayan, Vertical and limited lateral migration are the mainly patterns; (2) The asphaltic sandstone is from the mixed-source rocks of Cambrian and Lower Ordovician; It formed out of the destruction causes by the process of previous hydrocarbon migration; (3) The hydrocarbon accumulation model of Silurian strata is two stages of hydrocarbon accumulation, two stages of hydrocarbon adjustment, multi-point vertical migration, and limited lateral migration.
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  Fracture Parameters Optimization and Seepage Characteristics of Fracture Horizontal Well in Daqing Peripheral Oilfield

  CUI Maolei;WANG Yike;HUANG Xiaolei;YIN Fangchun;CHEN Zengshun;YANG Zhengming

  . 2011, 29(23): 45-49. https://doi.org/10.3981/j.issn.1000-7857.2011.23.005

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  Horizontal well with fracture has become one of main methods to exploit ultra-low permeability. In order to gain the in-depth knowledge of the effect of fracture parameters and seepage pattern on horizontal well productivity, a nonlinear flow mode optimizing the fracture parameters has been established based the actual case of horizontal well exploitation in Daqing Peripheral Oilfield. The nonlinear flow theory is applied to the mode and the optimization results are provided under the constant condition of both horizon length and fracture length. The fracture number and fracture intervals have a significance impact on exploitation effect. The larger fracture number is, the more obvious the effect of fracture intervals is. However, as number of fractures exceeds three, the effect of fracture intervals is reducing. Contrast to the characteristics of nonlinear flow with that of Darcy flow, the former has the lower productivity, higher remaining oil saturation, and higher water cut as soon as water is produced. In the nonlinear flow model, pressure isopleths are concentrated, pressure gradient is higher, and energy consumption is larger around the area of wellbore and injection-production line. Horizontal well has bigger pressure gradient, however, it is smaller than that for vertical well. The permeability in nonlinear flow model is directly proportional to pressure gradient.
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  A Technical Scheme of Secure Communication Based on SC Chaotic Synchronization Method

  SONG Zhiping;YU Hongjie

  . 2011, 29(23): 50-56. https://doi.org/10.3981/j.issn.1000-7857.2011.23.006

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  Chaotic masking communication program is the basic method and it is also easy to implement, however the required amplitude for the transmitted message is rather small. Therefore the transmitted message is sensitive to the channel noise, and then the decoding message has a lower accuracy. A method of chaotic synchronization based on the linear stability criterion is utilized, and a technical scheme of chaotic masking for secure communication is proposed. A nonlinear drive vector function of special chaotic state variable is constructed by a proper separation of the linear and nonlinear terms in a chaotic system. The transmitted message is injected into one element of the state vector. Thus the scheme increases the complexity of masking message and the decoding difficulty. Lorenz attractor and Chen attractor are used as an example to simulate the application of sinusoidal information transmitted by chaotic masking technique. The configuration of the Jacobi matrix is flexible and multiple choices. A simple and optimal chaotic masking scheme is given through comparative analysis. Numerical analysis shows that even if the amplitude of sine function information for transmission is quite large, there is no effect on the decoding accuracy of the information. The proposed scheme is effective.
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  Extraction of Alteration Information Based on Airborne Hyperspectral Image

  YANG Yanjie;ZHAO Yingjun

  . 2011, 29(23): 57-61. https://doi.org/10.3981/j.issn.1000-7857.2011.23.007

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  Based on CASI/SASI images' characteristics, the hyperspectral images processing procedure is established. The contents of each step and things, which should be paid attention to, are introduced. Before the extraction of alteration information, the data pre-processing should be well completed, the type of alterations in the study area should be determined, and the corresponding spectral database should be built. Some empirical approaches are made for those processing. Based on the experience, the various methods are described in detail and some algorithms are improved. Based on the spectrum characteristics of the rock containing ferrous iron-rich on the CASI images of Keping area, the ferrous iron-rich rock extraction algorithms are proposed. The field work has proved that the alteration information extracted is correct, and the extraction of ferrous iron-rich is a good guidance for uranium exploration. The rule determining the mineralization model in the study area is found through the alteration information extraction and spatial superposition analysis on mine points or mineral area. The special distribution of ferrous iron-rich rock has a strong correlation with the uranium abnormal. In the study area, the red sand rock is the passage for uranium, the dyke is the storage for uranium, and the ferrous iron-rich rock makes uranium settle around the dyke. Three new dykes of uranium abnormal are found in south part of Keping using the method.
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  Design and Implementation of Embedded Web Server System Based on SOPC

  CHEN Chuan;LI Xuemei;GUO Yong

  . 2011, 29(23): 62-65. https://doi.org/10.3981/j.issn.1000-7857.2011.23.008

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  The embedded Web server system is built with the EDK development tools of the FPGA hardware platform of Xilinx company. Based on the HTTP protocol, the TCP/IP socket programming technology is adopted for network communications between PC computer and target. using a high-speed image acquisition system. The equipment's ethernet port is used for the Web server remote access. Through the control commands for input, the system displays the image data, to realize the monitoring and controlling of remote site image data and device activity. In this paper, the functions of the system, the hardware design and the software design based on the Xilkernel Operation System (OS), LwIP protocol stack, XilMFS File System (FS), and socket network programming are discussed. The host end is tested to achieve browsing stored in the embedded Web server in the static page, at the same time, according to the browser input parameters, the indicator's on and off are used to control functions according to the input data. The image data stored in SDRAM could be browsed and the control indicator lamp could be on and off, according to the design.
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  Electronic Tongue Taste Detection Based on Principal Component Analysis

  JIANG Xingguo;HOU Hongbin;CHEN Zhencheng

  . 2011, 29(23): 66-69. https://doi.org/10.3981/j.issn.1000-7857.2011.23.009

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  According to the fundamental structure and the detection principle of the Light Addressable Potentiometric Sensor (LAPS) type electronic tongue, a taste recognition algorithm based on Principal Component Analysis (PCA) is designed. The signal detected by LAPS type electronic tongue is processed by PCA. The scores pictures of the first and the second principal components show that the spots of five basic tastes do not interfere with each other. Therefore, the five basic tastes could be more accurately recognized by PCA. Meanwhile, minimum distance method is employed to classify the principal components and the results of the experiments show that the method is prominent and the average rate of identification could reach at 96.54%. Final test results indicate that applying PCA to LAPS type electronic tongue has the huge potential for analyzing the taste of liquid, and also provides a scientific proof for developing the miniature LAPS type electronic tongue.
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  Control Strategy for Coiling Tension Based on RBF-Neural Network Inverse System

  JIANG Zeyi;MO Tiansheng;ZHANG Chao

  . 2011, 29(23): 70-73. https://doi.org/10.3981/j.issn.1000-7857.2011.23.010

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  Based on the research on coiling tension indirect control process, for the purpose to improve the accuracy of the constant tension take-up control, RBF neural networks and inverse system control theory are introduced. The physical characteristics of coiling tension control process are combined with, an inverse system model is established, and the simulation results are satisfactory. The model possesses the important guiding significance for actual productions.
Reviews
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  Treatment of Heavy Metals and Organic Contaminants by Titanium Dioxide Photocatalysis

  LIN Longli;LIU Guoguang;LU Wenying

  . 2011, 29(23): 74-79. https://doi.org/10.3981/j.issn.1000-7857.2011.23.011

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  Based on existing relevant scientific literatures, the review summarizes the impact factors of the degradation heavy metal ions and organic contaminants by titanium dioxide photocatalysis. The factors affecting photocatalytic activity include titanium dioxide crystal configuration, type of light irradiation and light intensity, pH value, oxygen, dosage of titanium dioxide, reactant concentration, reaction temperature, and some inorganic anions. The recent research progresses made in the mechanism of photocatalysis degradation heavy metal ions and organic contaminants is elaborated. The applications of research progresses including the impact of metal ions on the rate of photocatalytic oxidation of organic contaminants, the impact of organic contaminants on the rate of photocatalytic reduction of the heavy metals, and synergistic interaction between removal of metals and degradation of organic contaminants by photocatalysis are presented as well. At last, the difficulties involving feature research are analyzed and further investigations and applications of heavy metals and organic contaminants by titanium dioxide photocatalysis are pointed out.