18 November 2011, Volume 29 Issue 32
    

  • Select all
    |
    Articles
  • XIAO Xiangjiao;JIANG Hanqiao;LIU Yuewu;WANG Hongfeng;WAN Yizhao;WANG Xiaopei;OUYANG Weiping
    Abstract ( ) Download PDF ( ) HTML   Knowledge map   Save
    The temperature changes near the wellbore of the high temperature and high pressure well have clear influences on the gas production. In the Tarim Oilfield, the regularity of temperature variation near high temperature and high pressure gas well is a quite difficult problem. In order to ensure the normal gas production for the source wells of west to east gas pipeline, this regularity must be in-depth studied. A mathematical model for calculating the temperature near wellbore of high pressure gas well is established. The theoretical temperature curve near the wellbore is obtained by using the finite element method. The temperature changing rule is given during the open and shut down process of gas well. The temperature distribution near the wellbore is investigated by analyzing the heat flux through the wellbore. Calculation is based on actual data of the producing gas layer and non-producing layer, the wellbore temperature distributions around wellbore are analyzed, respectively. The results show that the changing magnitude of formation temperature in the segment of producing layer is smaller than that in the segment of non-producing formation.
  • HU Zhenfeng;WEI Yongqiang;REN Jikai;YU Jianhao;WEN Bin
    Abstract ( ) Download PDF ( ) HTML   Knowledge map   Save
    The recent development of domestic and international research on the field of coal mine safety hedge and emergency rescue was summarized. The construction of six systems in the work safety field in China was discussed. The reasons for that the research group chose system integration platform and designed 3D digitizing mine construction platform project were given. The three system integration platform construction, including personnel positioning system, pressurized air rescue system, and water supply rescue system, the implementation of 3D function, and key 3D GIS technology were introduced. By taking Beijing Haohua Energy Company's Muchengjian coal mine underground safety hedge system as an example, the platform realizes the unified integration of all kinds of underground information system and 3D visual management for a coal mine. It improves the overall linkage and emergency response ability of coal mine safety hedge system, which promotes the development of coal mine enterprise information construction.
  • IMINJAN Mubarak;YUNUS Kurax;HIZBILLA Mawlanjan;HUPUR Halmurat;LI Yuanjian
    Abstract ( ) Download PDF ( ) HTML   Knowledge map   Save
    To investigate the efficiency and the mechanism of the Uygur herb medicine Turkish Gall aqueous(KJA) in treating Ulcerative colitis and Colon cancer, we detect in vitro HT-29 cell apoptotic rate intervened by different concentrations of KJA and in vivo DNCB plus acetic acid induced UC's model rat apoptotic rate, morphological, pathological CMDI grading score changes of colon mucosa after being intervened by KJA. The results were compared between the normal group, the model control group, the mesalazine positive control group, the mesalazine plus KJA group, the KJA gavage group and the KJA enema group in three courses of treatment. It is demonstrated that the KJA would possibly have a therapeutic function in vitro to Colon cancer HT-29 cell by inducing cell apoptosis rate and in vivo to UC in rat by reducing colon mucosa morphological, pathological abnormal damages and inducing the apoptosis rate of colon mucosa damaged cells.
  • UPUR Hamulati;MAITISIDIKE Ayinuer;ABUDULAIHAITI Wuerguli;AJI Rouzibake;AIZIZI Renaguli;YOU Lina;YANG Na;YAN Xinghai
    Abstract ( ) Download PDF ( ) HTML   Knowledge map   Save
    To set up abnormal Hilit typing quantitative diagnostic criteria of uighur medicine for the bronchial asthma patients, in accordance with free disease clinical diagnostic information, 180 bronchial asthma patients were selected in the study of quantifying the diagnosis specialist counseling. The selected factors were analyzed by a modified multiple category logistic regression analysis to determine the contributions of the symptom-complex factors and the OR values and to identify the abnormal Hilit of the bronchial asthma. As a result, the meaningful symptoms were found in all abnormal Hilit syndromes according to the OR values. As a result, the chief symptoms of the abnormal savda type bronchial asthma are greenish urine, cyanotic tongue, cool skin, thready and hard pulse. Subsequent symptoms are dark and gloomy complexion, bitter taste.The chief symptoms of the abnormal kan type bronchial asthma are reddish complexion, reddish conjunctiva, short and fat tongue, and hotter skin. The second important symptoms are dry stools, deep-colored urine, yellow sticky sputum, thick and strong pulse. The chief symptoms of the abnormal balgham type bronchial asthma are sticky mouth, greasy, thick white fur, thick and low coloured urine, white and sticky tongue coating, and dry stool. Subsequent symptoms are metallic taste and pale conjunctiva. The chief symptoms of the abnormal sapra type bronchial asthma are yellowish complexion, yellowish conjunctiva, hot skin, yellowish urine, thready and floating pulse. Subsequent symptoms are thin tongue, bittersweet taste, dry and hard stool. The features of excess syndromes of the four abnormal Hilit syndromes are in line with the clinical practice. The symptom quantitative diagnosis of the abnormal Hilit excess syndromes provides an objective evidence for the clinical practice.
  • XIAO Mei;ZHANG Lei;MIAO Yonglu;LIU Wei;KOU Wenyu
    Abstract ( ) Download PDF ( ) HTML   Knowledge map   Save
    The background subtraction is an important method to detect the moving objects, the difficulty in which is the background reconstruction. Therefore an improved background reconstruction algorithm based on pixel intensity classification is proposed. According to the hypothesis that the background pixel intensity always appears in an image sequence with maximum probability, the adjacent frames will be classified as the same or different classes of intensity based on the frame difference and frame difference accumulation, and then merging procedure is run to classify the classes, finally intensity classes with maximum appearance probability are selected as the background pixel intensity values. Simulations results show that the algorithm could affectively avoid moving mixture and well reconstruct the background of vary scene. It also has quick speed, lower store space, and strong robust.
  • WEN Xingzhong
    Abstract ( ) Download PDF ( ) HTML   Knowledge map   Save
    To develop effective measures to ensure the safety operation of air traffic management, it is necessary to evaluate the security risks of air traffic management scientifically. In view of many grey factors affecting the safety of the air traffic management, the grey theory is used to evaluate the safety risk of the air traffic management. An indicator system of the safety risk evaluation of the air traffic management is built on the basis of the four kinds of factors, including human factors, equipment factors, environment factors and management factors. The weights of evaluation indexes are determined by means of the analytical hierarchy process(AHP). A model of safety risk assessment of the air traffic management based on the grey hierarchy theory is proposed. The expert score evaluation is used to evaluate the index layer of the security of the air traffic management. With this method,, the evaluation sample matrix of the index can be obtained. Then the grey evaluation weight matrix of each indicator in every index layer can be obtained. The safety risks of the air traffic management in a grey hierarchy theory can then be evaluated. The results of examples show that the model is effective, an overall security risk level of the air traffic management can be obtained with this method and an integrated evaluation method to evaluate the safety risks of the air traffic management can thus be developed. The result of the comprehensive evaluation provides a scientific basis for the air traffic management to work out security risk measures and preventive measures.
  • JIANG Xi;HAN Hongliang;DUAN Xiangguang;HAO Zhizhong
    Abstract ( ) Download PDF ( ) HTML   Knowledge map   Save
    In the iron and steel enterprises, the sintering process and sintering plant are the best paths for waste recycling. Any type of ferruginous waste generated as a byproduct of the different stages of steel production could be used in this way. In order to use the ferruginous mud resources scientifically and rationally, the experimental studies and a pilot industrial test for different ferruginous mud mixture ratios and different carbon proportions are conducted on basis of physical and chemical properties control of ferruginous mud. Test results show that use of ferruginous mud with higher levels of substances requisite in the sintering production, such as CaO and C, helps to reduce the cost of sintering ore, however, its fine granularity is detrimental to the sintering permeability. The indexes of yield and quality of sinter decrease with increasing carbon content of ferruginous mud, when it entirely substitutes carbon from sintering fuel. On the other hand, when 1/3 of the carbon content is provided by ferruginous mud instead of sintering fuel, sintering quality is close to the baseline values. The theoretical foundation and technical basis for higher efficiency of sintering using ferruginous mud are offered.
  • WU Zhide;ZHANG Xin;DU Rongjun;YI Haiyang
    Abstract ( ) Download PDF ( ) HTML   Knowledge map   Save
    The stability of Yinzhong highway fails to satisfy the requirements of the highway engineering. In order to know the deformation features of this highway during its construction, the FEM analysis software of NCAP-2D is used. The geotechnical material's nonlinear features, such as elastic-plastic relations, nonlinear joints, non-tensile characteristics, and orthotropic properties of the layered rock mass, are considered in the software. The Drucker-Prager yield criterion is applied in the numerical models, and the construction process of pile forming and soil filling are simulated with an element-free method. The basic data of displacement and stress after excavation are obtained when compared with those before excavation. Piles with different gaps and broken piles are simulated, and the plastic zone and displacement characteristics are analyzed. The results show that the top of jet grouting pile is in relatively obvious plastic state, because some loads on the soil between piles are transmitted to the piles. At the same time, the top of the piles experiences larger lateral displacement than the bottom, which could enhance the basement stability. The plastic zone and the displacement have a positive correlation when the gap between piles is changed, and the same for the soil and piles. But the area around the pile's top is where breakage would occur with whatever change of pile's gap. The plastic zone would obviously be concentrated around the broken piles, which would influence the foundation reinforcement effect. According to the field load test, after the treatment by high pressure jet grouting, the bearing capability of the foundation is, respectively, 2.08 times and 2.97 times of that of the untreated recently deposited loess and soft loess. And the actual monitoring settlement is only about 0.17 times of the calculated value. So, the treatment in this paper's situation has a good strengthening effects. The conclusion in this paper provides some guidance for highway's construction in the similar situations.
  • YANG Qiuming
    Abstract ( ) Download PDF ( ) HTML   Knowledge map   Save
    Based on the low-frequency meridional wind of 850 hPa over East Asia for May-July in 2011 on the time scale of the 20-30 days, a series of the principal oscillation pattern (POP) models are built, and independent forecast experiments of POP models are carried out for the propagation of the low-frequency zone associated with the heavy precipitation over the lower reaches of the Yangtze River valley in Mid-July 2011 for the extended range of the 10-30 days. The results show that the skill score of the correlation prediction up to 20 days ahead of time can reach more than 0.50 in the 60 forecasts, and the variations of the low frequency meridional wind of the key region are well predicted in connection with a disastrous rain on July 18, 2011 over the lower reaches of the Yangtze River valley.
  • LIU Ye;MA Hui
    Abstract ( ) Download PDF ( ) HTML   Knowledge map   Save
    In view of the clustering of P2P networks and the issues of increased communication latency and network costs caused by mismatch between the logical topology and the physical topology, this paper proposes a mixed three-layer P2P network model. The model adjusts the network structure dynamically based on the position and the property features of nodes, so that the performance of searching resources can be improved adaptively. The simulation result shows that the P2P networks can achieve a high recall ratio with low search delay and cost.
  • 学术争鸣
  • ZENG Zuotao;WANG Xun;
    Abstract ( ) Download PDF ( ) HTML   Knowledge map   Save
    The paper "The impacts of climate change on water resources and agriculture in China" (Nature 43, 43-51, 2010) fails to follow scientific methods by selecting one-sided data sets and research results to support their argument that the warming has a significant negative impact on water resources and agriculture. This one-sided paper is not only a disservice to the academic community, but also has generated unnecessary panic responses from public that China will not be able to feed its people since warmer temperatures in China will reduce crop yields significantly. The purpose of this paper is to clarify some of the basic facts about the true impacts of the warming on water resources and agriculture in China and discuss some relevant methodological issues.
  • Reviews
  • CHEN Zongmao
    Abstract ( ) Download PDF ( ) HTML   Knowledge map   Save
    Pesticide residue in agricultural products is an important aspect in food safety. The application of chemical pesticide in the agriculture was begun since 1938 and the pesticide residue problem was emerged in the end of 1950's. The publication of the "Silent Spring" written by Rachal Carson in 1962 revealed the prologue of pesticide residue. It was paid more attention in the world with the development of pesticide toxicology. The MRL of pesticide residue in food was decreased around 100 times in the 60 years period between the sixties of last century and 2010. The new challenge of pesticide residue in the future was discussed by the author from the aspects of the adoption of acute reference dose (ARfD) in the toxicity assessment, the development of pesticide toxicology, the accumulative toxicology of various pesticides and the difference of toxicology in chiral compounds of pesticide. The risk assessment, the revealing of contamination source and the cleaning production were put forward by the author as the major techniques in controlling of pesticide residue in agricultural products.