13 July 2010, Volume 28 Issue 15

    

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  Call for Favorite China Car

  . 2010, 28(15): 3-3.

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Articles
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  Dynamic Imaging of Mild Cognitive Impairment with 11C-PIB

  . 2010, 28(15): 21-25.

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  The early diagnosis and treatment is very important for patients with Alzheimer's Disease (AD), which can be progressed from Mild Cognitive Impairment (MCI). The aims of this study include: (1) to determine the localization and the load of the beta-amyloid protein in the brains of MCI patients in vivo using 11C-PIB PET dynamic imaging; (2) to evaluate the clinical value of 11C-PIB PET imaging in MCI. 21 subjects, which were divided into three groups: 8 patients with MCI, 6 with AD, and 7 as Health Control (HC). All patients underwent sequential emission PET scans of brain after 11C-PIB administration. All 11C-PIB PET images were visually interpreted and analyzed by the Region of Interest (ROI) method. The attenuation-corrected PET images were semi-quantitatively analyzed using Standardized Uptake Value (SUV). Dynamic SUV data and curves were obtained as a function of time from 0 to 55 minutes of post-injection time. The ratio of radioactivity clearance and ratio of SUV of targeted brain regions vs cerebellum at 45min were calculated for statistical analysis. The dynamic images show that 11C-PIB passes cross the blood-brain barrier very rapidly, and clears rapidly in healthy brain. The results of applying the visual and ROI method indicate that AD patients typically show marked retention of 11C-PIB in related cortex where a large amount of amyloid is deposited. In MCI patients, the PET image of some patients are HC-like, and others are AD-like. Therefore, the MCI patients can be divided into 2 groups (HC-like group and AD-like group) for analysis, and the visual interpretations are consistent with the statistical analysis results. There are no significant difference observed in the data between HC-like group and HC group, and between AD-like group and AD group, respectively. It is concluded that 11C-PIB PET imaging can provide reliable quantitative information about beta-amyloid protein in living AD and MCI patients, and 11C-PIB PET imaging is a promising method to evaluate the prognosis of MCI.
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  Comparison Between Different Modified Magnetic Nanoparticles in Biosafety

  . 2010, 28(15): 26-30.

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  L929 cells are used to study the effects of Magnetic Nano-Particles (MNPs) on cytotoxicity and evaluate the biological safety. MTT colorimetric assay was used to study the effects of different doses and durations of MNPs on the cells, and to evaluate the toxic effects of MNPs on cells and bio-safety. The results show that the leaching liquor with the MNPs modified with APTS is mainly of the first and the second grades well within the standard of cytotoxicity, but that of the MNPs modified by DMAB for 48h reaches the level of the fourth grade with a fair cytotoxicity. Compared with DMAB modified MNPs, the research in vitro reveals that the APTS modified MNPs have fewer inhibitions on the cell survival rate. Different doses and durations of MNPs see some differences in their effects on cytotoxicity, a certain dose may be found for MNPs with time-dependent lower inhibition of cell proliferation.
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  Data Mining for Chinese Traditional Medicine Prescription Based on Computing Science

  . 2010, 28(15): 31-35.

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  With Chinese Traditional Medicine (CTM) prescriptions as the object of study, a data mining platform is constructed by using database mining, approximate inference and machine learning, based on computing science. An CTM Prescriptions Database System (CPDBS), an CTM Intelligent Analysis System (CPIAS) and an CTM Classification Model Recognition System are developed with Support Vector Machine (CPSVM) to study the knowledge of CTM prescriptions. Progress has been made on insight discovery, qualitative and quantitative computation of key knowledge and classification model recognition of CTM prescriptions. It is shown that with the data mining of CTM prescriptions as the entry point of CTM diagnostics study, an effective way may be found to transfer human experience to systematic knowledge, which has a practical meaning on modernization of CTM.
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  Cooperative Inducing Effects of Three Plant Growth Regulators on the Chilling Resistance of Sweet Pepper (Capsicum annuum) Seedlings

  . 2010, 28(15): 36-41.

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  To study the cooperative inducing effects of coronatine (COR), abscisic acid (ABA), and mineral fulvic acid (MFA) on the chilling resistance of plants, the sandy culture method was used to identify the effects of mepiquat chloride on the lipid peroxidation, electrolyte leakage, reactive oxygen species and antioxidant enzyme activities in sweet pepper (Capsicum annuum) seedlings under cold stress. Sweet pepper seedlings were irrigated with 10mL per plant of COR, ABA, MFA, and their mixture, respectively. The seedlings were planted at temperature of 10～15℃ for 60d, and then cold stress under 5℃ for 48h. The growth of seedlings and the development of lateral roots were promoted by the mixture. The cooperative inducing effects of three plant growth regulators on the chilling resistance is remarkable. Under cold stress, the activities of antioxidant enzymes such as superoxide dismutase (SOD, EC 1.15.1.1), catalase (CAT, EC 1.11.1.6) and peroxidase (POD, EC 1.11.1.7) in leaves were increased. As a result, the efficiency of reactive oxygen species elimination was enhanced. With the higher content of proline and sugar as the effect of abscisic acid in the leaf, the harms of the membrane were relieved by the mixture.
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  Simulation of Mold Growth on Building Walls

  . 2010, 28(15): 41-45.

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  In order to analyze the conditions of mold growth on the wall, the climate data of Changsha are used as the boundary condition to simulate the mold spore germination on room's indoor and outdoor walls with WUFI-BIO software. The results show that the actual water content of fungal spores is related to its initial water content, the environmental temperature and the relative humidity. The initial water content of fungal spores has a less impact on spore germination than the relative humidity, whose influence would gradually decrease over time. Without consideration of solar radiation and rainwater erosion, or other unfavorable factors, except in winter, when it is not easy for mold to grow on outdoor walls, in other seasons, spore germination and mycelium growth would be promoted. Moldy indoor walls are mainly found in mid-May to mid-June and August to mid-September. The organic pollutants on indoor wall surface may help the mold spores germinate ahead of time, even enhance their growth. And the entire wall is at an increasing risk of mildew. The growth of mold is harmful to human health. In order to reduce the growth rate of mold during their growth period, it is necessary to take some measures to minimize the indoor relative humidity, and keep the indoor environment in a good condition.
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  A PCR Correction Method of MPEG-2 Re-multiplexer Adapted for FM Synchronous Broadcast

  . 2010, 28(15): 45-49.

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  The Program Clock Reference (PCR) is the time base of decoding video and audio in MPEG-2 system. A MPEG-2 decoder uses the PCR to control the decode time and the present time of video and to realize the synchronization of video and audio. The PCR correction is one of the key technique for the MPEG-2 remultiplexer design. This paper proposes an improved and practical method of the PCR correction for the design of MPEG-2 remultiplexer through analysis of problems in the PCR correction method currently used in MPEG-2 remultiplexer． With the correction method, the re-multiplexer can solve the problem that the timing of the PCR value described in the PCR field is not in accord with the timing of the decoder received in the PCR field in the packet, due to the buffering of the MPEG-2 signal in the processing of remultiplexing, therefore, it can solve the problems of PCR jitter and buffer overflow in the processing of MPEG-2 decode, which would happen with a wrong PCR correction method. A decoder can reconstruct the clock signal of the encoder from the PCR value, and keep the clock in synchronization between decoder and encoder. Furthermore the audio signal after re-multiplexer with the new PCR correction method can meet FM synchronous broadcast requirements for a more accurate time.
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  IDS Method Based on Genetic Improved Fuzzy C-Means

  . 2010, 28(15): 49-52.

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  In order to overcome the shortcomings of the algorithm of Fuzzy C-Means (FCM), namely, the extreme sensitivity to the initial data and the liability to come to local optimum points, this paper proposes a combination of the genetic algorithms and the improved fuzzy C average value methods and the use of the examination rate and the mistaken examination rate as the evaluation indices for the invasion examination algorithm performance. The simulation analysis is carried out for the invasion examination performance of three kinds of algorithms related to FCM, improved FCM and improved FCM based on the heredity. The result indicates that the method, based on the genetic improved FCM algorithm (GIFCM) enjoys higher examination rate and lower mistaken examination rate. This algorithm can find an effective application in exceptionally invasion examination.
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  Fracture Development and Accumulation History of Fractured Reservoirs in Tongnanba Belt, Northeastern Sichuan Basin

  . 2010, 28(15): 53-57.

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  The fractured reservoirs are one of the most important prospecting targets in northeastern Sichuan Basin. However, the development features of fractures and the filling history of these fracture reservoirs were not well studied. This paper mainly analyzes the fracture characteristics by image logging and determines the charging time of gas reservoirs in Tongnanba structure belt by fluid inclusion measurements. The main conclusions can be summarized as follows. Firstly, the fractured reservoirs are mostly distributed in ooid limestone and grey doloarenite, respectively, in T1j2 and T1f3 formations, and dominate by high-angle or vertical fractures. Secondly, the trend of fractures is consistent with that of neighboring faults due to the northeast-southwest compression stress due to Daba Mountain structure and medium-late Yanshan Movement, which indicates that fractures might be formed in the era of late Jurassic. Thirdly, the gas charging time is about late Jurassic (160¡«148Ma) as confirmed by fluid inclusion measurements. Fourthly, it is the most important factor for the gas filling time that the development time of fractured formation matches with the gas-generating peak of the source rock in Tongnanba structure belt
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  Dynamic Pressure Behavior in Vertically Fractured Wells of Tight Reservoir

  . 2010, 28(15): 58-61.

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  For non-Darcy flows of tight reservoir and special flow patterns in vertically fractured well, a trilinear flow model is developed to study the early-time and immediate-time flow stages, taking the effect of wellbore storage and the skin effect of vertical fracture into consideration. The effective wellbore radius is used to describe the effect of the threshold pressure gradient in the latter time flow regime. Combining the trilinear flow model with the effective wellbore radius, a transient flow well-testing model in tight reservoir is built, which is solved by the least squares method. At the same time, an analysis is made based on these solutions that include the effects of various parameters, such as the fracture conductivity, the skin on the fracture, and the threshold pressure gradient. It is shown that the larger the dimensionless fracture conductivity and the smaller the pressure drop, the smaller the energy loss will be; the pressure response in early-time and intermediate-time stages is mainly influenced by the skin factor; the larger the threshold pressure gradient and the more significant the dimensionless pressure increase, the larger the energy loss will be in the later stage.
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  Prediction of Formation Porosity Pressure in Deep Formation

  . 2010, 28(15): 62-66.

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  With various data of well logging, drilling and fracture in Xuer gas reservoir of Xinchang structure, predictions were made by using different approaches including equivalent depth method, Eaton method and effective stress method, for the formation porosity pressure section in this area. According to previous studies for the active mechanism of abnormal high pressure in western Sichuan depression, it is shown that the abnormally high pressure in the foreland basin of the Upper Triassic Formation is mainly affected by uncompacted hydrocarbon booster, booster and dewatering of clay minerals, tectonic uplift. Therefore, in this paper, the Eaton method is adopted to establish the formation porosity pressure section. By verifying the predicting model and evaluating single wells, it is indicated that the predicting model has a very high accuracy to meet the demand of production. According to the depth of stratum, the Xinchang structure can be divided into four pressure areas, including the normal pressure belt, the transition pressure belt, the abnormal high pressure belt and the relatively smooth belt. All of above results may provide some guidance for subsequent drilling jobs and regional stress field researches.
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  Performance of Microbial Enhanced Oil Recovery Under Different Recovery Percentages of Reserves

  . 2010, 28(15): 67-70.

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  In order to study the performance of microbial enhanced oil recovery under different recovery percentages of reserves, four groups of cores with different oil saturation extents were injected into 0.2 pore of the culture medium inoculated with the bacteria producing biosurfactant and biopolymer. Then the core was closed to cultivate the bacteria, in the reservoir temperature, beneficial for oil production. After 10 days, the water-oil displacement experiment was carried out and the bacterial concentrations in the flooding water were detected by the plate count method. By comparing the oil displacement efficiency of the core inoculated with bacteria with that of the core without bacteria, it is shown that, in the process of the experiment, the displacement pressure, the bacterial concentrations and the final displacement efficiency all vary with the different recovery percentages of reserves. It is concluded that, with the different recovery percentages of reserves, the variations of oil components, oil-water phase ratio and the fluid ability affect the reproduction of microorganisms and the accumulation of its metabolite concentrations and the gross amount, as a result, the recovery efficiency increases firstly and then decreases with the continuous increase of the recovery percentage of reserves. The study provides some guidance in choosing the microbial strain and the time of the microbial enhanced oil recovery and the displacement rate.
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  Preparation and Catalytic Activity of CeO2/CNTs

  . 2010, 28(15): 71-74.

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  CeO2/CNTs composite nanoparticles supported by self-made carbon nanotubes(CNTs) were prepared by the liquid-phase chemical deposition and the influences of surfactant on the preparation of composite nanoparticles were studied. The shape, the particle size and the crystal structure of the prepared nanoparticles were investigated by using TEM, XRD and FT-IR techniques. The results indicate that in certain conditions, the surfactant's bridging function improves the loading of the active components effectively, and evenly loaded CeO2/CNTs composite nanoparticles can be prepared based on Sodium Dodecyl Benzene Sulfonate. The supporting CeO2 nanoparticles were face-centered cubic crystals, with particle size of about 6.4nm. The mechanism of loading metal oxides on the surface of CNTs is discussed. On this basis, CNTs, CeO2 and CeO2/CNTs were used as the catalyst, respectively, in the nitric acid oxido-degradation of Dongdu weathered coal. The results show that CeO2/CNTs enjoy the best catalytic properties and could enhance the yield of the humic acid significantly as compared with other catalysts. Also, the prepared humic acid had the largest E4/E6 ratio, and the molecular weight of humic acid is smaller.
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  Analysis of Fatty Components from the Seed of Barley

  . 2010, 28(15): 75-78.

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  The amount of fatty and the compositions of fatty acids in the seeds of barley were determined and analyzed. Rude fatty acids from the seeds of barley were extracted by Soxhler extractor and the acid-hydrolysis method. After being methyl-esterified with the presence of KOH/MeOH, the components of fatty acids were analyzed by GC/MS. The results show that the extracting amounts of rude fatty acids using these two methods are 1.87g/100g and 1.98g/100g, respectively. 12 and 14 kinds of fatty acids were obtained from the two methods. The main components are linoleic acid (52.20%, 53.27%), palmitic acid (22.75%, 22.15%), oleic acid (16.35%, 14.63%), and linolenic acid (4.65%, 5.48%). Most of the fatty acids are polyunsaturated fatty ones, which constitute more than 75% of the total mass. The results could offer some basic data to the food research related with barley.
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  Alcohol Extraction Technology of Abnormal Savda Munziq Granular

  . 2010, 28(15): 79-82.

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  To develop the optimal alcohol extraction technology of Gancao, Dijincao, Tiexianjue in the Abnormal Savda Munziq Granula, with the content and the amount of alcohol extractive of glycyrrhizin as index, single factor experiments were carried out. The four factors that influence the extraction result, the quantity and the concentration of alcohol, the extracting time and the frequency, were optimized. The extracting process is as follows: to extract twice with 55%, 65%, 75% alcohol, of amount of 10, 12, 14 times, 1.0, 1.5 and 2.0 hours each time. Then the L9(34) orthogonal design is used to find the best alcohol extraction technology of Gancao, Dijincao, Tiexianjue,
  Xiangqinglan. A balanced sampling is adopted in the range of each key factor to make each experiment highly representative. With the well-distributed nature of these factors, the orthogonal layout can ensure all experiments serve their purpose. The results show that the extracting time and amount do not have marked influence but the concentration of alcohol does. Due to the insignificant influence of the amount of alcohol and the extracting time, the optimum extraction technology A2B2C3 may be replaced by A2B1C1, that is, to extract twice with 65% alcohol, of amount of 10 times, 1 hour each time. The extraction method is reasonable, feasible and convenient to be applied to production. The preparation technology for Abnormal Savda Munziq Granular can be similarly obtained.
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  Modeling and Simulation of the Driving System Based on Fuzzy PI Control in Electric Vehicles

  . 2010, 28(15): 83-87.

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  Automobile industry has to face problems such as energy shortages, environmental pollution and global warming, along with its contributions in economic development and improvement of people's living standard. The electric vehicle is the most effective way to solve problems related with energy and environmental pollution. The performance of an electric vehicle is closely related with the driving system to be operated on various driving conditions. This paper combines the balance equation for the vehicle movement with the equation of motor mechanical properties to establish a mathematical model of the driving system of Electric Vehicle (EV). Fuzzy PI control strategy is used in the model for the optimal control and the model is simulated by the software Simulink. Simulation results show that the mathematical model of the driving system of the electric vehicle can represent the vehicle running states accurately. Fuzzy PI control strategy optimizes the control of the driving system and improves the performance of the simulation in tracing the speed. The simulation model is very robust and applicable to simulate the driving system of electric vehicles.
Reviews
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  Review on Climate Changes of Tropical Cyclones and Typhoons

  . 2010, 28(15): 88-96.

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  This paper reviews recent advances on studies of the climate changes related with tropical cyclones and typhoons that would cause severe disasters. Several key points are identified in this paper. As shown by the comparisons of the observed data of the tropical cyclones and typhoons during the last 60 years, the reliability of the earlier data is lower than the later ones, that is, what observed during the last 30 to 40 years. The reliability increases with the intensity of tropical cyclones. The results as calculated by the observed data on six Oceans indicate that the multi-decadal variability of tropical cyclones and typhoons does exist. The intense tropical cyclone activity has increased since about 1970. Besides observations, both statistical and dynamical downscaling methods can to a certain extent simulate the tropical cyclones and typhoons, but with large uncertainties. Most multi-dynamical and statistical models considering increased human emissions and global warming give a consensus of prediction that the strong typhoons (hurricanes) over the northwestern Pacific Ocean (North Atlantic Ocean) are likely to enhance by the end of the 21st century. The tropical cyclones and typhoons as the extreme climate events would cause huge damages to mankind. It is difficult to make the climate predictions exactly by using the present dynamical and statistical downscaling methods. The further investigations on the impact factors and prediction methods should narrow the uncertainties.
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  Atmospheric Pressure Low Temperature Plasma Jets and Their Biomedical Applications

  . 2010, 28(15): 97-105.

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  Atmospheric low temperature plasmas, as a new emerging field, have recently received an increased attention through several novel applications, such as surface modifications of polymers, absorption and reflection of electromagnetic radiation, especially in the biomedical field with their outstanding advantages, such as the generation in atmospheric pressure, low gas temperature, and high activity. The plasma jet devices generate plasma plumes in open space (surrounding air) rather than only in confined discharge gaps. Thus, they can be used for direct treatments with no limitation on the size of the object to be treated. Atmospheric pressure plasma jet devices driven by DC source, AC source, RF source, microwave and pulsed-DC source are reviewed in this paper, as well as their physical characteristics, the effect of inactivating microorganisms, and their biomedical applications. Finally, the problems existing in generating atmospheric low temperature plasma jet, the possible solutions, and the prospect of their application fields in the future are discussed.
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  Genome Information, Code Evolution, Folding Dynamics and Entropy Production: Several Fundamental Problems in Theoretical Biology

  . 2010, 28(15): 106-111.

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  The rationalization of biology is discussed in an information-centered context. The studies in the field of theoretical biology are reviewed which include the following topics. (1) The formation and construction of the genome recognition code. A set of statistical quantities describing base composition and base correlation can serve as the genome recognition code. (2) The genome evolution direction and the maximum information principle. It is proposed that the quanlity of the function-coding information of a genome grows with time in the course of evolution. It is proposed also that the Shannon information quantity of the local DNA segments obeys the maximum information principle. (3) The adaptive evolution of the genetic code. It is proved that the prevalent standard amino acid code is a mutational deterioration-minimal code of an adaptive evolution and it is demonstrated that the genetic code satisfies both the principles of robust stability and evolvability. (4) The protein folding dynamics based on quantum transition. The protein folding rate formula is deduced based on quantum transition between torsion states by using conformation dynamics. All theoretical results (including the rate and its dependence on chain length, inertia moment and temperature, etc.) are consistent with the updated experimental data. (5) The cell switch and entropy production. The dynamics of lysogenic/lytic transition of lambda phage - the simplest form of the life - is studied from a set of differential equations. The entropy production rate of the typical cell switch is calculated. It is proved that the dynamics of this particular system obeys some topological theorem and thus the obtained results are of general nature.
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  Computer Vision Technology for Intelligent Automation of Food Processing

  . 2010, 28(15): 112-117.

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  Computer vision technology plays an important role and becomes one of key technologies in the intelligent automation of food processing because of its outstanding advantages, such as its high speed of detection, contactless nature, and high precision. In recent years, both theoretical methods and practical technologies in the field of computer vision have been developed rapidly. In this paper, the research achievements and successful applications of computer vision technologies in food industry are reviewed, including some key topics, such as process monitoring, quality supervision and food safety. Moreover, the authors elucidate the significance of computer vision technologies in the intelligent optimizing controls and the cooperation and coordination of networked multi-robot food processing systems for the intelligent automation of food industry. Finally, the prospect and development trends of computer vision technologies for food processing are discussed.