13 July 2010, Volume 28 Issue 13

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  • . 2010, 28(13): 19-23.
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    A Finite Element(FE) model of the coach framework is established. Based on an analysis of the existing evaluation methods for residual space in real tests and simulations, especially their shortcomings, a new evaluation method of transmission-type residual space is proposed. Then the finite element model of the coach framework is used to simulate this new evaluation method. It is shown that the coach superstructure would be plunged into the residual space, as against the regulatory requirements. The strength of the coach superstructure is less than desirable, so a method is proposed to improve the coach body framework—a ring type structure and added foot beams to connect waist rails and floor beams. The simulation results show that the improved coach body framework is satisfactory and the new evaluation method is simple, practical, accurate and reliable.
  • . 2010, 28(13): 24-28.
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    Body area communication based on quasi-electrostatic field is a new technology to implement the inter-connection between personal pocket electronic devices. The effect of body movement on performance of body area communication system was studied. Channel gains on body standing, making time, and running were measured in experiments. Based on the experiments' data, the cumulative distribution function of channel gain was acquired and compared with several general statistics distribution. Channel gain obeyed normal distribution. Parameters were estimated using maximum likelihood method. The mean, standard deviation and confidence interval were acquired. Then, channel statistical and simulation model has been established to analyze the system performance. Within the environment of Gaussian white noise, the effect of body movement on system performance of amplitude shift keying modulation was simulated. The general methods of body area communication channel modeling and simulation were given. Results show that Bit Error Rate (BER) increased slightly with fierce degree of body movement.
  • . 2010, 28(13): 29-34.
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    In this paper, a nonlinear method is used for the chaotic control of a single H-R neuronal model. The nonlinear time delay feedback function is added to the right hand side of the first differential equation of equations of a single Hindmarsh-Rose(H-R) neuron model. Gain factor and time-delay are taken as control parameters. Through the numerical calculations and analyses, a certain range of the combination of gain factor and time-delay is found, in which, the chaotic burst pattern of inter-spike interval sequences of H-R neuron can be controlled onto a spikes-period pattern or a multi-period of these patterns automatically. The main periodic patterns of H-R neuron are patterns of the spike-period, double spikes-period, 3 spikes-period, 4 spikes-period and 6 spikes-period and their multi-period pattern. The bifurcation diagrams of the chaotic neuron under control are provided. Choice of delay does not depend and rely on the period of unstable periodic orbits embedded within the chaotic attractor. The chaotic burst orbit will be controlled onto the certain type of periodic patterns of inter-spike interval automatically, to achieve the purposes of information identification.
  • . 2010, 28(13): 35-39.
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    Over-excavation is an inevitable fact in tunnel excavation. Based on the principles of the Mahalanobis Distance Discriminating Analysis (DDA), a distance discriminating analysis model is proposed in this paper to predict over-excavation of underground opening. According to engineering practice, the main factors affecting overbreaking in tunnels include the geological characteristics of rock mass and the geological constitution, which are considered in the forecast DDA model. Five parameters influencing the over-excavation of opening, including two groups of joints, one group of layer surface, extension and space between structure faces, are selected as geometric parameters. Twenty-one sets of engineering data in an underground opening are used as the training samples. Corresponding discriminating functions are obtained to classify the samples to be discriminated. The re-substitution method is used to verify the stability of the DDA model and the ratio of mistake-discrimination is equal to zero after the DDA model is trained. Some field survey data in a pump-storage hydroplant were used to test the discriminant ability of the DDA model. The results show that the prediction results are identical with the actual situation, with high predicted accuracy and low misdiscrimination rate. The DDA model can be used in practical engineering.
  • . 2010, 28(13): 40-46.
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    In this paper, a new high resolution scheme based on wavelet singularity analysis is proposed. Wavelet transform is used to analyze the flow fields and the wavelet coefficients are used to control the numerical method. In order to verify the effectiveness of the new method, five typical examples are calculated: 2D supersonic flow over a forward-facing step; 2D transonic flow over the RAE 2822 airfoil; 2D transonic flow through the VKI-LS59 turbine cascade; 3D transonic flow in axial compressor rotor, NASA Rotor 37 and 3D transonic flow in axial fan rotor, NASA Rotor 67. The numerical results show that this new high resolution scheme can be used in complex internal and external flow fields, and the new method can better capture the discontinuity (such as rarefaction wave, contact discontinuity and shock wave) in the flow fields. Compared with TVD schemes (Total Variations Diminishing schemes), ENO schemes (Essentially Non-Oscillatory shock capturing schemes), the new method is more efficient because TVD and ENO are only used for the grids with singularity. It is also shown that with the new method, the same resolution for the shock wave can be achieved under the same computational grids but with much reduced computation time, about one fifth of that by TVD/ENO schemes.
  • . 2010, 28(13): 47-51.
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    In consideration of problems of current magnetic rheology damping devices concerning overheating, structural complexity, low magnetic field utilization ratio and precipitations, based on the requirement for the vehicle's shock absorption, which should be proportionally controlled with the damping device, this paper presents a design of a new-type magnetic rheology damping device for vehicles that adopts an external magnetic field of bypass type and a one-way liquid flow, for which the advanced development and test phases have already successfully completed. The new magnetic rheology damping device has prominent features in its working principle and structures, including the efficient use of magnetic field, the matching of pull and push forces, and the handling of precipitation and forces of multi-degrees of freedom. The damping part is connected to the structure in a serial manner, and the coil is inside the cylinder near the tube wall, to reduce the size in the radial direction, to secure a good radiation condition and for convenient maintenance. The effects of the exciting current, the oscillation amplitude and the frequency on the damping force are experimetally analyzed, and the new magnetic rheology damping device is shown to be able to generate the pull and push damping force to effectively match the proportional control structural design, which satisfies the requirement in attenuating the vehicle's vibration. The parallel disc slit type damping can enhance the efficiency of the magnetic field in generating the magnetic rheology damping force, to extend the damping force's range and to ease its control. The new device provides a new technical way for the performance improvement, an effective feasible new antihunt device and an important vehicle's antivibration application.
  • . 2010, 28(13): 52-57.
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    By using NDVI data, the continuous change of vegetation prior to the Ms 8.0 Wenchuan earthquake is investigated in this paper. Firstly, according to a comparison year by year, it was found that, to the east of Longmenshan Fault, in Sichuan Basin, the vegetation was degraded by 0~20% from 2005 to 2006. The phenomenon was caused by drought in 2006. Spatially, the movements of Sichuan Basin plate played an important role on the Wenchuan earthquake. Therefore, according to the relationship between drought and earthquake, the degradation could be regarded as one of precursory anomalies prior to the Wenchuan Earthquake. Secondly, the vegetation in early May in Longmenshan Fault was degraded significantly from 2007 to 2008. Moreover, the same phenomenon did not happen in other adjacent faults, like Xianshuihe Fault. As is well known, prior to earthquakes, there may be changes of electric and magnetic fields, gas emissions, groundwater levels, temperature, surface deformations, and so on. These changes are all related with the vegetation degradation to some extent, and they could be seen as a short-term anomaly prior to the 2008 Wenchuan Earthquake. Furthermore, the two anomalies developed spatio-temporally from distant regions to near regions with respect to the epicenter. Additionally, some evidences were found to re-confirm the effects of vegetation anomaly. For example, the anomaly of Earth resistivity was observed 2 years before the earthquake. However, there are some limitations for detection of vegetation anomaly prior to earthquake due to other influencing factors, such as growth periodicity and topography. Further research is needed.
  • . 2010, 28(13): 58-61.
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    Among numerous tertiary recovery technologies, Alkaline-Surfactant-Polymer(ASP) flooding is one of the most important Enhanced Oil Recovery (EOR) methods. In this method, the ASP solution system exhibits the characteristics of non-Newtonian power-law fluid. A well test model with consideration of storage and skin effects is established in this paper based on non-Newtonian power-law fluid in infinite, constant pressure and no-flow circular boundary homogeneous reservoirs. The effective wellbore radius was obtained by
    introducing the dimensionless definitions of the effective wellbore radius and integrating parameters. Theoretical curves were obtained and further analyzed. In addition, the expressions of the early-time storage stage and the late-time radial flow phase were simplified, with two analytic solutions being derived by Laplace transformation. The results show that the early-time response stage is influenced by the combined parameter of storage and skin and the radial flow stage is affected by the power-law index for the homogeneous well test curve. The proposed model can provide a theoretical foundation for well test data analysis of ASP flooding.
  • . 2010, 28(13): 62-67.
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    To accurately explain the fine structure and sort out the subsurface tectonic form and its distribution, the accuracy of the structure maps is a very essential factor, therefore, whether the structural map can correctly reflect the true subsurface tectonic form plays an important role in identifying the structure accurately under the ground. This paper proposes an absolute value rule and the "package" principle to identify tectonic form rapidly and accurately for the truth structure and structure pitfalls. First of all, on the basis of the absolute value of the contour line, the tectonic form is identified, and at the same time, the structural high points are found; secondly, the theoretical tectonic form is compared with the seismic cross section, combined with flat and profile, to verify the correctness of interpretation results; at the last, the structure pitfalls can be identified. With an oil field as an example, the principle is used to distinguish true and false structures, excluding the structural pitfalls, fully demonstrating the practicality of the principle. The research provides a reasonable basis for finding trap quickly and reasonably.
  • . 2010, 28(13): 68-72.
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    Considering the complexity of the fractured reservoir characterization, based on current geological modeling methods and technologies for fractured reservoirs at home and abroad, a four-step geological modeling method is proposed for dual medium reservoirs, that is, a structure model to be used by the matrix system and the fracture system in the first step, petro-physical parameter models for the matrix system in the second step, a geometrical model for the fracture net and then a 3D parameter model in the third step, and a model to be checked with dynamic data in the fourth step. The forecast fracture density is used as a constraint condition for the pre-superimposition seismic inversion, and then, based on the detailed logging data, the special fractured buried hill mutation reservoir of Bohai sea area is analyzed. The 3D distribution of the fractures is forecast according to the interpretation results of the imaging logging, the 3D fracture piece model is visualized, finally the discrete fracture pieces are transformed into 3D continuous quantificational property models. With Jinzhou25-1S oilfield fractured buried hill mutation reservoir as an example, based on the elaborate description of structure, lithology and fractures of the fractured reservoir, the reservoir 3D models of structure, fracture distribution and properties are established by means of such modeling softwares as Fred, Petrel etc and the quantificational characters of the fractured reservoir are described.
  • . 2010, 28(13): 79-100.
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    In order to study the therapeutic effect of focused ultrasound on cervical High-Risk HPV (HR-HPV) infection, a total of 90 women with high-risk cervical HPV infection were divided randomly into the ultrasound group (30 cases), the interferon group (30 cases) and the control group with no treatment(30 cases). The remission, ineffective and negative rates were compared in the third and sixth months after treatment. It is shown that in the third month, the negative rate was 53.3% for the ultrasound group, 48.3% for the interferon treatment and 31.0% for the control group. In the sixth month, the negative rate was changed to 86.2% for the ultrasound group, 79.3% for the interferon treatment and 53.6% for the control group. Compared with the control group, both ultrasound and α-2b interferon can reduce the titre of HR-HPV(P<0.05). There is no obvious difference between ultrasound and α-2b interferon groups(P>0.05). The results show that the ultrasound treatment can control the infection of cervical HR-HPV effectively and safely.
  • . 2010, 28(13): 82-86.
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    For the purpose of preparing docetaxel with a high yield, a mild and convenient semi-synthetic process of docetaxel is adopted. The target compound is prepared in four steps. 10-deacetyl baccatin III, the starting material, is reacted with benzyl chloroformate to form C-7 and C-10-protected 10-deacetyl baccatin III, which is then reacted with (3R,4S)-1-tert-butoxy-carbonyl-3-(1-ethoxy-ethyloxy)-4-phenylaz-etidin-2-one and followed by hydrogenolysis to form a 2'-(1-ethoxy-ethyloxy)-N-off benzoyl-N-tert-butyl carbonyl oxy-gen-10-deacetyl taxol, and then, the target compound is finally obtained by the acid hydrolysis. The key step is the selective protection of C-7 and C-10 hydroxyl groups of 10-deacetyl baccatin III. The effects of main factors on every reaction process are analyzed, to establish the optimized reaction conditions of every step. The target molecules and intermediates are characterized by MS and NMR. The results indicate that the synthetic process is of low cost, easy for handling and with an overall yield of 50% from 10-deacetyl baccatin III.
  • . 2010, 28(13): 87-91.
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    To explore the effects of X-ray on weight,histological structure and expression of Bax protein in liver of developing filial mice,160 mice of 6~7 days after birth were radiated with different dosages (0, 1, 3, 5, 7Gy) of X-ray. Changes of liver and body weight were examined, histological structure was observed using bio-microscopy,and the expression of Bax protein was measured by immunohistochemical staining in filial mice liver at 1, 5, 10 and 20d after irradiation. Results show that X-ray influences the growth and development of the filial mice liver. The liver weight of filial mice of the experimental groups is lower than that of the control group 5~20d after irradiation (P<0.05 or P<0.01), except experimental groups with 1Gy; the body weight of filial mice of the experimental groups is lower than that of the control group 5~20d after irradiation(P<0.01); the expression intensity of Bax protein in the liver of filial mice is significantly increased with the increase of the dose; the structure of hepatic lobule is unclear, hepatic plate is thinner, hepatic sinusoid is stronger, accompanied with hepatocyte disfiguration, irregular arrangement, nucleus atrophy, and vacuolization, after irradiation.
  • . 2010, 28(13): 92-96.
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    In order to extract water-soluble saccharides from discarded tobaccos effectively, and to study their biological activity, the microwave technology is used in extraction of water-soluble polysaccharides from discarded tobaccos and the optimal process of extraction was obtained by the method of continuous microwave radiation. On the basis of one-factor tests, the effects of extraction temperature, microwave power, extraction time and liquid-to-solid ratio on the microwave extraction of water-soluble saccharides were analyzed by the orthogonal experiment and the range analysis. The results of range analysis show that the factors affecting extraction rate are in the following order in their importance: ratio of solid to liquid>microwave power>extraction time>temperature. The optimized conditions are:
    1:30 of the ratio of solid to liquid, 400W of the microwave power, 20 min of the extraction time and 60℃ of the temperature. The extraction rate of 28.54% can be obtained under the above conditions, an increase of 6.39% and 6.92%, respectively, as compared with the classical method and the direct water extraction This method enjoys advantages such as high efficiency, energy-saving, yield stability and time-saving.
  • . 2010, 28(13): 97-100.
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    Aloe is a famous medicine material, which contains many mineral elements such as calcium, magnesium, iron and zinc. It is necessary to determine the quantity of metal elements in aloe for the development of the aloe industry. The Microwave Plasma Torch Atomic Emission Spectroscopy (MPT-AES) is applied in analysis and testing of aloe in this paper. The contents of calcium, magnesium, iron and zinc in Chinese and Yuanjiang aloes were determined, respectively, by the 510 model MPT spectrograph. Various experimental parameters (including analytical wavelength, microwave forward power, support gas flow rate, carrier gas flow rate and oxygen shield gas pressure) were obtained and optimized systematically. Under the optimal conditions, the detection limits for Ca, Mg, Fe, Zn were 5.62, 3.03, 78.36, 25.41ng/mL, respectively, with linear ranges of 0.05~100, 0.01~100, 0.2~20, 0.1~20?滋g/mL. All of the RSDs were less than 1.48%, and the recovery rates of these elements were around 96.5%~102.4%. The results show that the method is simple, rapid, accurate and of great application value. The contents of metallic elements in Chinese aloe and Yuanjiang aloe are almost the same, but Chinese aloe contains more iron than Yuanjiang aloe.
  • . 2010, 28(13): 101-104.
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    On-line handwritten signature verification is one kind of biometric identity recognition technology. Response rate of verification is a key factor for a handwritten signature verification system as well as recognition correct rate and noise robust property. An improved DTW algorithm is discussed to reduce the recognition time, which optimizes the conventional DTW algorithm's structure with the method of dynamic programming, and fastens the template matching speed in real-time handwriting identification. At the same time this paper puts forward a weighted distance calculation formula based on weighting to the stability of every stroke. The experiment has proved that this method is effectual. This method reduces the False Reject Rate(FRR) while guaranteeing high recognition rate. The matching distance is confined properly when the number of models increases. The experimental results show that the algorithm not only reduces the amount of calculation data, but also minimizes the duration of the whole processing. The advantage of the new algorithm is more obvious with the increment of models. Experiments show that this algorithm is highly efficient in computation, and generates nice result of stereo matching.
  • Reviews
  • . 2010, 28(13): 105-110.
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    Mammalian cell cloning is the most compelling high-technology in life sciences in the late 20th century. It is important because of its roles played in the reproduction of good breeding stock, reduction of the number of experimental animals, reserving of animal genetic diversity, saving of endangered animals, transgenic animal breeding and other aspects. A variety of cloning animals have been made successful, but with a low efficiency and frequent abnormality in birth weight and physiological conditions, which are discussed in detail in this paper, together with the current developments of animal cloning, and the technologies involved in cloning animals. The methods to remove the nuclei from oocytes and to reconstruct embryos are highlighted. The application prospects are also commented.
  • . 2010, 28(13): 111-115.
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    Anemarrhena asphodeloides are commonly used in clinical researches. Their quality is affected by various factors, including sources, cultivation practices, growth conditions, processing methods and others. In order to control the quality, various quality indicators and methods were adopted. The most principal chemical composition of Anemarrhena asphodeloides, are timosaponins and xanthones. It is, therefore, important to establish quality standards to evaluate the contents and other factors of the two compounds in medicinal substances. Sarsasapogenin can be obtained after the major timosaponins acid hydrolysis, so the old indices are still valid. This paper reviews the quality control markers and methods of Anearrhena asphodeloides Bunge in recent years, and the quality and various factors affected such as producing areas,cultivating measures, collecting time, processing methods, etc.