08 April 2011, Volume 29 Issue 11-10
    

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    To investigate the effect of long-term administration of marine collagen peptides on the life-span of SD rats, 160 SD rats of four weeks old were divided into the control group and MCP-treated groups, with 40 rats in each group (male:female=1:1). Control rats were fed with standard basal diets and the rats in the experimental groups were fed with 2.25%, 4.5% and 9% MCP in the control diet until their natural death. The bodyweight, food consumption and food efficiency were recorded throughout the experiment. The activity of serum antioxidant enzymes GSH-PX and SOD and the level of MDA were examined every six months. The results show that the MCP does not signifiantly influence body weight, food consumption or food efficiency of rats of either sex throughout the life span. The survival analysis shows that the median lifespan, the lifespan of the last 30% survivals and the maximal life span of MCP treated groups were notably longer than those in the control group. MCP did significantly inhibit the age-related decrease in the activities of antioxidant enzymes and the age-related increase in the levels of lipid peroxidation product in both sexes. When treated with MCP for 18 months and 24 months, the activities of serum GSH-PX and SOD enzymes of the 4.5% and 9% MCP treated rats were significantly higher than those of the control rats, whereas the serum level of MDA in the 4.5% and 9% MCP treated groups were significantly lower as compared with the control group. Therefore, the long-term administration of MCP could significantly extend the lifespan of SD rats, which might be attributed to the anti-oxidative property of marine collagen peptides.
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    The interrelationship between tongue epithelial cell apoptosis regulation of portein and pathological changes of liver depression in perimenopausal syndrome is investigated to provide a solid experimental basis for related clinical diagnosis and treatment. 50 cases of healthy women and 150 cases of perimenopausal syndrome patients were randomly divided into the control group and experimental groups. Liver depression points were evaluated by syndrome element differentiation; Maturation Index (MI) and Maturation Value (MV) of tongue epithelial cells were determined by Papanicolaou staining; the apoptotic rate of tongue epithelial cells was measured by flow cytometric; and the apoptosis regulation of portein was determined by immunohistochemical. The results show that liver depression points of syndrome patients are significantly higher than those of healthy women; pathological changes of liver depression, and the middle cells MI of tongue epithelial cells are positively correlated, and the surface cells MI and MV of tongue epithelial cells are negatively correlated; pathological changes of liver depression, and apoptotic rate, Fas, Bax of tongue epithelial cells are positively correlated, and Bcl-2 of tongue epithelial cells are negatively correlated. It is concluded that the liver depression is one of the cores of pathogenesisa in the perimenopausal syndrome, and the tongue epithelial cells maturity, apoptotic rate and apoptosis related regulation of gene are interrelated.
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    The changes of several physiological indexes including the relative permeability of membrane, MDA, proline and soluble sugar are studied at the seedling stage of medicinal halophyte Lycium ruthenicum under different NaCl stress levels in order to understand better the mechanism of its salt tolerance. It is shown that the relative conductivity and the MDA content increase with the increase of NaCl concentration and stress time, and the increase rate is relatively higher under higher NaCl concentration than lower concentration. The content of proline also increases significantly with the increase of NaCl concentration, and the increases under 200, 300, 400 and 500mol/L NaCl stress are 405.78%, 800.11%, 773.78% and 747.51%, respectively. In addition, the content of proline first increases and then decreases with the stress time. At the initial stage of salt stress, the content of soluble sugar first decreases and then increases with the increase of salt concentration. With the increase of stress time, the variation trend of soluble sugar is consistent with that of proline, but the maximum value appears at the 18th day after salt stress, and the increases under different NaCl concentrations are 64.62%, 83.15%, 106.60%, 207.00% and 186.70%, respectively, as compared with that at the initial stage. Relatively speaking, the accumulation of proline in leaves of Lycium ruthenicum is more sensitive to salt stress, which is an effective mode to adapt the environmental stress. In conclusion, Lycium ruthenicum could absorb a great amount of soluble organic osmotica to adapt harmful environment.
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    Using the technique of strong electric field ionization discharge, O2 are ionized, decomposed, and introduced into high activity radicals and O2/H2O is turned into the initiator. SO2 and NOx are oxidized into the droplets of H2SO4 and HNO3 by radicals and the initiator is injected into the reaction chamber with no absorbent and catalyst. It is shown that the mole concentration ratio of oxygen radical to SO2 and NOx is the decisive factor. NOx is removed firstly, and SO2 starts to be removed when the removal rate of NOx reaches an optimal value, with n being 2—3. The temperature is a main influencing factor for SO2 and NOx removal, a lower temperature is better. H2O plays an important role in forming hydroxyl radical and improving the removal process of SO2 and NOx.
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    Based on the routine observational data, a diagnostic analysis is performed of the severe storm on 18—19 July 2008 in Weifang, Shandong Province. It is shown that the heavy storm is caused by the interaction between a weak cool front in the westerlies and the warm and wet air along the path of typhoon owing to the powerfulness and stability of the subtropical high and atmospheric blocking in Baikal. The southeast warm and wet air along the path of typhoon is the main vapour source of the rainstorm. The heavy rain occurs in the powerful updraft condition with convergence at low level and divergence at high level. The convergence layer is thick, which is the cause of heavy rain. The 925hPa layer is an important layer with respect to the event because of its role in supplying plentiful vapour. Concentrated period of time of positive vorticity center corresponds to the period of heavy rain, which is propitious to the development of convection. It occurred in the north of the very stiff and dense section of moist isentropes and in the low troposphere of strong convective instability (MPV1<0). The region of positive MPV2 at low level has a very good correlation with the location of rainstorm. The distribution of MPV2 at low level may provide a good indicator for the forecast of rainstorm region.
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    The reservoir of Xu4 formation of Fenggu Structure is characterized by high buried depth, poor reservoir property, and little velocity's difference between sand and mud, etc. In view of these characteristics, using seismic multiple attributes inversion based on neural network and stochastic simulation based on geological statistics to predict sandbody distribution. The concrete step is that firstly the efficient pre-analysis on target curve and the well seismic calibration are made. And seismic attributes are optimally sorted and selected based on the correlation between single seismic attribute and target curve. Secondly, the non-linear relation between multiple attributes and target curve is searched and the three-dimensional inversion volume is obtained through the training of Probabilistic Neural Network. Finally, a model of sandstone content is built using this volume as the constrained condition, and then the inter-well distribution of sandbody is predicted. The practical application shows that using this method can effectively reduce the mistiness of prediction and improve the precision of prediction. Besides, spatial distribution and superimposition relationship of different sandbodys can be accurately displayed using the method. It has a certain value for the sandodys prediction.
  • . 2011, 29(11-10): 49-52.
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    For residual gas, especially in two special situations during in-situ gas content testing, including the case when the content of residual gas is too small to measure and the case where the gas content should be obtained quickly, the residual gas field problems in testing are summarized. (1) In the measurement of the content of low rank coal seam gas of slow desorption, the residual gas may be too small so that the conventional methods can not be used or the error will be too large. (2) For rapid desorption test bed methane gas, in the crushed coal sample in the testing of residual gas, a small amount of methane may be lost to make the residual gas results too low. The paper proposes a new numerical regression method (Langmuir curve regression) for residual gas, which is different to the normal test and is quick, accurate and efficient with respect to preparation to the actual measurement data.
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    The focal length of the lens in the spatial filter should simultaneously satisfy the requirement of vacuum and the minimum spherical aberration. In order to filter the high frequency components, the divergence angle of the filter must be less than a certain value according to the system requirement. So the aperture of the filter hole used in the high power laser system is about 20 times of the diffraction limitation. At the same time, the scope of the location of the filter hole in the optical axis is reasonable as long as the location within the focal depth. In addition, the model was built by means of the optical design software to simulate validation. The simulation results show that the designed spatial filter according to the method presented in the paper can effectively filter out the high frequency components and stray light in the system.
  • Xiu-wen YANG
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    The coupling efficiency of spherical fibre optics and wedge-shaped fibre optics is measured by the experimental method. The curve reflecting that the coupling efficiency of fibre optics changes with the wedge angle of wedge-shaped fibre optics and the sagita of spherical fibre optics is given. By the experiments, the coupling properties had been analyzed and compared. It had been shown that coupling efficiency between a spherical fibre optics and a wedge-shaped fibre optics increases with the increase of wedge angle, the curve of the coupling efficiency assumes a quick uptrend by varying the wedge angle from 20.6° to 30.3° and from 40.6° to 55.2°, The curve of the coupling efficiency assumes a mitigative uptrend by varying the wedge angle from 30.3° to 40.6° and from 55.2°to 76.5°; coupling efficiency between the spherical and wedge-shaped fibre optics linearly increases with the increase of sagita of spherical fibre optics; coupling efficiency increases with the decrease of the distance between wedge-shaped and spherical fibre optics. The curve of the coupling efficiency assumes a quicker uptrend by varying the distance from 0.09mm to 0.05mm, the curve of the coupling efficiency assumes a downtrend by varying the distance from 0.04mm to 0.01mm.
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    The mKdV equation with variable coefficients is reduced to an ordinary differential equation through a traveling wave transformation. With the aid of the symbolic computation software Mathematica as well as the extended F-expansion method recently proposed on the basis of the analogical method, the homogeneous balance principle and Jacobian elliptic function method, the concentrated formulas of exact solutions are derived if the coefficients of the mKdV equation satisfy some specific constraint conditions. By using the relations between values of P, Q, R and corresponding solutions F(ξ) for the first kind of elliptic equation, from the concentrated formulae of solutions, a large number of explicit exact solutions, especially, the solutions expressed in two different Jacobian elliptic functions are obtained. In the limit cases, that is, when the module approaches 1 or 0, these explicit exact solutions degenerate into the soliton-like solutions and the exact solutions in the form of trigonometric functions, respectively. It is worthwhile to mention that the method used here is straightforward, concise and powerful and can be used for solving many other similar nonlinear partial differential equations which would appear in the fields of mathematical physics, natural sciences and applied sciences.
  • Reviews
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    Mars is our Earth's neighbor with many aspects very much similar to the Earth, Mars is sometimes considered as the future Earth, which means that the Earth's internal structure, surface, and space environment, may evolve in a long period, to those similar to the present Mars. Therefore, based on a comparison with the Earth, to explore and investigate Mars is important not only to the revelation of the universe mystery, but also to better understanding of our Earth. Since the 1960's, the spacecrafts have been sent to explore Mars. There were more than 40 spacecrafts (with some failures) to explore Mars and some important results were obtained in the last more than 40 years. These results help us understand Mars, such as the Martian internal structure and surface, atmosphere, ionosphere and magnetosphere, and so on. This paper analyzes the results of the exploration and investigation on Mars, including the Martian internal structure, surface, atmosphere, ionosphere, intrinsic magnetic field and magnetosphere, as well as the solar wind interaction with Mars. A brief introduction on the main scientific questions and significances of the Mars exploration and investigation is also presented.
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    Biological invasion is now one of the six hot research topics in modern ecology. Modeling the invasion processes, the diffusions and the spreading mechanisms of invasive species including diseases is important not only for theoretical purposes, but also for practical purposes, such as in ecological risk assessments, and optimal control and management of those invasive species. In this paper, the widely adopted models of biological invasion are systematically reviewed such as diffusion-reaction equations, integral-difference models, space-discrete models, and stochastic models. The fundamental issues of modeling biological invasions are discussed, and the characteristics and analytic conditions of various models are analyzed with typical examples and recent research results. Various modeling techniques are compared, and some commonly used methods in solving biological invasion models are outlined, including numerical computing and simulating, exact solutions, methods for functional differential equation and qualitative analysis of differential equations. Some key and unsolved problems in building mathematical models of biological invasion, and future research directions are also discussed.