植物对环境污染的磁学响应机理研究

With development of industry and acceleration of urbanization, problems of air quality as well as their influences on human health have recently been regarded highly by current international communities and governments. Generally, industrializations can result in exhausting of a lot of industry gases and dusts, while urbanization can cause increasing of modern vehicles. Comparing with traditional chemical methods, magnetic method is simple, rapid, exact, low-cost and non-destructive for monitoring air pollution and has been widely applied in domestic and international studies. In this thesis, with an aim of better monitoring air pollution, we selected plants (highroad-side perennial pine trees (Pinus pumila Regel) along a highroad linking Beijing City and the Capital International Airport, and tree bark and tree ring core samples (willow, Salix matsudana) nearby a smelting industry in northeast Beijing) for magnetic studies. With systemic magnetic measurements on these samples, magnetic response mechanism of contamination（e.g. tree leaves, tree ring）to both short- and long-term environmental pollution has been constructed, and accordingly the pollution range, degree and process of different time-scale human activities could be assessed. A series of rock magnetic experiments of tree leaves show that the primary magnetic mineral of leaf samples was identified to be magnetite, in pseudo-single domain (PSD) grain size range of 0.2-5.0 μm. Magnetite concentration and grain size in leaves are ascertained to decrease with increasing of sampling distance to highroad asphalt surface, suggesting that high magnetic response to traffic pollution is localized within a distance of about 2 m away from highroad asphalt surface. On the other hand, highroad-side trees and rainwater can effectively reduce the concentration of traffic pollution-induced particulate matters (PMs) in the atmosphere. This study is the first time to investigate the relationship of smelting factory activities and vicissitudes of environment with tree rings by magnetic methods. Results indicate that magnetic particles are omnipresent in tree bark and trunk wood. Magnetic techniques including low-temperature experiment, successive acquisition of IRM, hysteresis loops and SIRM measurements suggest that magnetic particles are predominated by magnetite in pseudo-single domain state. Comparison of magnetic properties of tree trunk and branch cores collected from different directions and heights implies that collection of magnetic particles depends on both sampling direction and height. Pollution source-facing tree trunk wood contains significantly more magnetic particles than other sides. These indicate that magnetic particles are most likely intercepted and collected by tree bark first, then enter into tree xylem tissues by translocation during growing season, and are finally enclosed in a tree ring by lignifying. Correlation between magnetic properties such as time-dependent SIRM values of tree ring cores and the annual steel yields of the smelting factory is significant. Considering the dependence of magnetic properties in sampling directions, heights, and ring cores, we proposed that magnetic particles in the xylem cannot move between tree rings. Accordingly, the SIRM and some other magnetic parameters of tree ring cores from the source-facing side could be contributed to historical study of atmospheric pollution produced by heavy metal smelting activities, isoline diagrams of SIRM values of all the tree rings indicate that air pollution is increasing worse. We believed that a synthetic rock magnetic study is an effective method for determining concentration and grain size of ferromagnets in the atmospheric PMs, and then it should be a rapid and feasible technique for monitoring atmospheric pollution.

基于显式分形插值的高保真地震数据重建方法研究

Based on the fractal theories, contractive mapping principles as well as the fixed point theory, by means of affine transform, this dissertation develops a novel Explicit Fractal Interpolation Function（EFIF）which can be used to reconstruct the seismic data with high fidelity and precision. Spatial trace interpolation is one of the important issues in seismic data processing. Under the ideal circumstances, seismic data should be sampled with a uniform spatial coverage. However, practical constraints such as the complex surface conditions indicate that the sampling density may be sparse or for other reasons some traces may be lost. The wide spacing between receivers can result in sparse sampling along traverse lines, thus result in a spatial aliasing of short-wavelength features. Hence, the method of interpolation is of very importance. It not only needs to make the amplitude information obvious but the phase information, especially that of the point that the phase changes acutely. Many people put forward several interpolation methods, yet this dissertation focuses attention on a special class of fractal interpolation function, referred to as explicit fractal interpolation function to improve the accuracy of the interpolation reconstruction and to make the local information obvious. The traditional fractal interpolation method mainly based on the randomly Fractional Brown Motion (FBM) model, furthermore, the vertical scaling factor which plays a critical role in the implementation of fractal interpolation is assigned the same value during the whole interpolating process, so it can not make the local information obvious. In addition, the maximal defect of the traditional fractal interpolation method is that it cannot obtain the function values on each interpolating nodes, thereby it cannot analyze the node error quantitatively and cannot evaluate the feasibility of this method. Detailed discussions about the applications of fractal interpolation in seismology have not been given by the pioneers, let alone the interpolating processing of the single trace seismogram. On the basis of the previous work and fractal theory this dissertation discusses the fractal interpolation thoroughly and the stability of this special kind of interpolating function is discussed, at the same time the explicit presentation of the vertical scaling factor which controls the precision of the interpolation has been proposed. This novel method develops the traditional fractal interpolation method and converts the fractal interpolation with random algorithms into the interpolation with determined algorithms. The data structure of binary tree method has been applied during the process of interpolation, and it avoids the process of iteration that is inevitable in traditional fractal interpolation and improves the computation efficiency. To illustrate the validity of the novel method, this dissertation develops several theoretical models and synthesizes the common shot gathers and seismograms and reconstructs the traces that were erased from the initial section using the explicit fractal interpolation method. In order to compare the differences between the theoretical traces that were erased in the initial section and the resulting traces after reconstruction on waveform and amplitudes quantitatively, each missing traces are reconstructed and the residuals are analyzed. The numerical experiments demonstrate that the novel fractal interpolation method is not only applicable to reconstruct the seismograms with small offset but to the seismograms with large offset. The seismograms reconstructed by explicit fractal interpolation method resemble the original ones well. The waveform of the missing traces could be estimated very well and also the amplitudes of the interpolated traces are a good approximation of the original ones. The high precision and computational efficiency of the explicit fractal interpolation make it a useful tool to reconstruct the seismic data; it can not only make the local information obvious but preserve the overall characteristics of the object investigated. To illustrate the influence of the explicit fractal interpolation method to the accuracy of the imaging of the structure in the earth’s interior, this dissertation applies the method mentioned above to the reverse-time migration. The imaging sections obtained by using the fractal interpolated reflected data resemble the original ones very well. The numerical experiments demonstrate that even with the sparse sampling we can still obtain the high accurate imaging of the earth’s interior’s structure by means of the explicit fractal interpolation method. So we can obtain the imaging results of the earth’s interior with fine quality by using relatively small number of seismic stations. With the fractal interpolation method we will improve the efficiency and the accuracy of the reverse-time migration under economic conditions. To verify the application effect to real data of the method presented in this paper, we tested the method by using the real data provided by the Broadband Seismic Array Laboratory, IGGCAS. The results demonstrate that the accuracy of explicit fractal interpolation is still very high even with the real data with large epicenter and large offset. The amplitudes and the phase of the reconstructed station data resemble the original ones that were erased in the initial section very well. Altogether, the novel fractal interpolation function provides a new and useful tool to reconstruct the seismic data with high precision and efficiency, and presents an alternative to image the deep structure of the earth accurately.

ω循环型预条件矩阵及其应用

In this paper, we apply the preconditioned conjugate gradient method to the solution of positive-definite Toeplitz systems, especially we introduce a new kind of co-circulant preconditioners Pn[ca] by the use of embedding method. We have also discussed the properties of these new preconditioners and proved that many of former preconditioners can be considered as some special cases of Pn[co\. Because of the introduction of co-circulant preconditioners pn[a>], we can greatly overcome the singularity caused by circulant preconditioners. We have discussed the oo-circulant series and functions. We compare the ordinary circularity with the co-circularity, showing that the latter one can be considered as the extended form of the former one; correspondingly, many methods and theorems of the ordinary circularity can be extended. Furthermore, we present the co-circulant decompositional method. By the use of this method, we can divide any co-circulant signal into a summation of many sub-signals; especially among those sub-signals, there are many subseries of which their period is just equal to 1, which are actually the frequency elements of the original co-circulant signal. In this way, we can establish the relationship between the signal and its frequency elements, that is, the frequency elements hi the frequency domain are actually signals with the period of 1 in the spatial domain. We have also proved that the co-circulant has already existed in the traditional Fourier theory. By the use of different criteria for constructing preconditioners, we can get many different preconditioned systems. From the preconditioned systems PN[values for co and then we can use these preconditioned systems instead of the given Toeplitz systems to get some approximate solutions. Theoretical analysis and actually numerical experiments have already proved the effectiveness of this approximation. By combining the co-circulant with the boundary condition, we can overcome end effects efficiently. We have also presented the co-circulant boundary condition and compared it with the helix boundary condition. Furthermore, we can also get another new boundary condition: the mixed boundary condition. Numerical experiments have proved that the co-circulant boundary condition is better than the mixed one while the helix boundary condition is the worst among them.

基于工程地质力学的岩土工程加固理论、技术与实践

In the engineering reinforcement of-rock and soil mass, engineers must consider how to obtain better reinforcing effect at the cost of less reinforcing expense, which, in fact, is the aim of reinforcement design. In order to accomplish the purpose, they require not only researching the material used to reinforce and its structure, but also taking into account of several important geological factors, such as the structure and property of rock and soil mass. How to improve the reinforcing effect according to engineering geomechanical principle at the respect of the reinforcement of engineering soil and rock mass is studied and discussed in this paper. The author studies the theory, technology and practice of geotechnical reinforcement based on engineering geomechanics, taking example for the soil treatment of Zhengzhou Airport, the effect analysis of reinforcement to the slope on the left bank of Wuqiangxi Hydropower Station and the reinforcing design of the No. 102 Landslide and unique sand-slide slope on the Sichuan-Tibet Highway. The paper is comprised of two parts for the convenience of discussion. In the first part, from the first chapter to the fifth chapter, trying to perform the relevant research and application at the viewpoint of soil mass engineering geomechanics, the author mainly discusses the study of reinforcing soft ground soil through dynamical consolidation and its application. Then, in the second part, from the sixth chapter to the eleventh chapter, the study of new technologies in the rock slope reinforcement and their application are discussed. The author finds that not only better reinforcing effect can be gained in the research where the principle and method of rock mass engineering geomechanics is adopted, but also new reinforcing technologies can be put forward. Zhengzhou Airport is an important one in central plains. It lies on Yellow River alluvial deposit and the structure of stratum is complex and heterogeneous. The area of airport is very large, which can result in differential settlement easily, damage of airport and aircraft accident, whereas, there are no similar experiences to dispose the foundation, so the foundation treatment become a principal problem. During the process of treatment, the method of dynamic compaction was adopted after compared with other methods using the theory of synthetic integration. Dynamic compaction is an important method to consolidate foundation, which was successfully used in the foundation of Zhengzhou Airport. For fill foundation, controlling the thickness of fill so as to make the foundation treatment can reach the design demand and optimum thickness of the fill is a difficult problem. Considering this problem, the author proposed a calculation method to evaluate the thickness of fill. The method can consider not only the self-settlement of fill but also the settlement of the ground surface under applied load so as to ensure the settlement occurred during the using period can satisfy the design demand. It is proved that the method is correct after using it to choose reasonable energy of dynamic compaction to treat foundation. At the same time, in order to examine the effect of dynamic compaction, many monitor methods were adopted in the test such as static loading test, modulus of resilience test, deep pore pressure -test, static cone penetration test and the variation of the pore volume measurement. Through the tests, the author summarized the discipline of the accumulation and dissipation of pore pressure in Yellow River alluvial deposit under the action of dynamic compaction, gave a correct division of the property change of silt and clay under dynamic compaction, determined the bearing capacity of foundation after treatment and weighted the reinforcing effect of dynamic consolidation from the variation of the soil particle in microcosmic and the parameter of soil mass' density. It can be considered that the compactness of soil is in proportion to the energy of dynamic compaction. This conclusion provided a reference to the research of the "Problem of Soil Structure-the Central Problem of Soil Mechanics in 21 Century ". It is also important to strengthen rock mass for water conservancy and electric power engineering. Slip-resistance pile and anchoring adit full of reinforced concrete are usually adopted in engineering experience to strengthen rock mass and very important for engineering. But there also some deficiency such as the weakest section can't be highlighted, the monitor is inconvenient and the diameter of pile and adit is very large etc. The author and his supervisor professor Yangzhifa invented prestressed slip-resistance pile and prestressed anchoring adit full of reinforced concrete, utilizing the advantage that the prestressed structure has better anti-tensile characteristic (this invention is to be published). These inventions overcome the disadvantages of general slip-resistance pile and anchoring adit full of reinforced concrete and have the functions of engineering prospecting, strengthening, drainage and monitor simultaneous, so they have better strengthened effect and be more convenient for monitor and more economical than traditional methods. Drainage is an important factor in treatments of rock mass and slop. In view of the traditional drainage method that drainage pore often be clogged so as to resulted in incident, professor Yangzhifa invented the method and setting of guide penetration by fiber bundle. It would take good effect to use it in prestressed slip-resistance pile and anchoring adit full of reinforced concrete. In this paper, the author took example for anchoring adit full of reinforced concrete used to strengthen Wuqiangxi left bank to simulate the strengthened effect after consolidated by prestressed slip-resistance pile, took example for 102 landslide occurred along Sichuan-Tibet highway to simulate the application of slip-resistance pile and the new technology of drainage. At the same time the author proposed the treatment method of flowing sand in Sichuan-Tibet highway, which will benefit the study on strengthening similar engineering. There are five novelties in the paper with the author's theoretical study and engineering practice: 1. Summarizing the role of pore water pressure accumulation and dissipation of the Yellow River alluvial and diluvial soil under the action of dynamical consolidation, which has instructive significance in the engineering construction under the analogical engineering geological conditions in the future. It has not been researched by the predecessors. 2. Putting forward the concept of density D in microcosmic based on the microcosmical structure study of the soil sample. Adopting D to weight the reinforcing effect of dynamic consolidation is considered to be appropriate by the means of comparing the D values of Zhengzhou Airport's ground soil before with after dynamically consolidating reinforcement, so a more convenient balancing method can be provided for engineering practice. 3. According to the deep research into the soil mass engineering geology, engineering rock and soil science, soil mechanics, as well as considerable field experiments, improving the consolidating method in airport construction, from the conventional method, which is dynamically compactmg original ground surface firstly, then filling soil and dynamically layer-consolidating or layer-compacting at last to the upgraded method, which is performing dynamical consolidation after filling soil to place totally at the extent of the certain earth-filling depth. The result of the dynamical consolidation not only complies with the specifications, but also reduces the soil treatment investment by 10 million RMB. 4. Proposing the method for calculating the height of the filled soil by the means of estimating the potential displacement produced in the original ground surface and the filled earth soil under the possible load, selecting the appropriate dynamically-compacting power and determining the virtual height of the filled earth soil. The method is proved to be effective and scientific. 5. According to the thought of Engineering Geomechanics Metal-Synthetic Methodology (EGMS), patenting two inventions (to the stage of roclamation, with Professor Yang Zhi-fa, the cooperative tutor, and etc.) in which multi-functions, engineering geological investigation, reinforcement, drainage and strength remedy, are integrated all over in one body at the viewpoint of the breakage mechanism of the rock slope.

Fractionation and analysis of Artemisia capillaris Thunb. by affinity chromatography with human serum albumin as stationary phase

A method for the screening and analysis of biologically active compounds in traditional Chinese medicine is proposed. Affinity chromatography using a human serum albumin (HSA) stationary phase was applied to separate and analyze the bioactive compounds from Artemisia capillaris Thunb. Five major peaks and several minor peaks were resolved based on their affinity to HSA, two of them were identified as scoparone (SCO, 6,7-dimethoxycoumarin) and capillarisin (CAP). CAP shows a much higher affinity to HSA than SCO. The effects of acetonitrile concentration, eluent pH, phosphate concentration and temperature on the retention behaviors of several major active components were also investigated, and it was found that hydrophobicity and eluent pH play major roles in changing retention values. The results demonstrate that the affinity chromatography with a HSA stationary phase is an effective way for analyzing and screening biologically active compounds in traditional Chinese medicine. (C) 2000 Elsevier Science B.V. All rights reserved.

New method for analysis of Chinese herbal complex prescription and its application

Traditional Chinese medicine (TCM) is a great treasure of China, the analysis of which is an arduous task. The viewpoint that all chemical constituents of Chinese herbal complex prescription should be analyzed as a black box is elucidated for the first time. Intelligent multi-mode multi-column chromatographic system (IMMCC) with its hybrids is the basic method and HPLC Unified Method is the breakthrough for the black box analysis. Dang-Gui-Bu-Xue-Tang was selected as a typical TCM and a systematic separation method from non-aqueous mobile phase to pure water mobile phase was put forward in order to convert unknown sample to known sample. The a, c values and UV spectra of 66 components of Astragalus, 78 components of Angelica and 71 components of Dang-Gui-Bu-Xue-Tang were obtained. Intelligent optimization and peak identification method and software for complex samples were developed and the optimum multi-step multi-binary gradient curve of mobile phase for Astragalus was ascertained. The maximum error and minimum error of predicted retention time for all components of Astragalus are 8.62% and 0.05% respectively. All components of Astragalus were compared with those of Angelica and it is found that many components of Astragalus are the same as those of Angelica, while the contents of these components are different. Many components of Dang-Gui-Bu-Xue-Tang are also the same as those of Astragalus and Angelica with different contents.

当代大学生消费价值观与消费行为的调查研究——北京大学生中的消费主义倾向及有关影响因素研究

The aim of this study was to investigate consuming values and behaviors in Chinese college students, to detect the factorial structure in consuming values, and to explore possible determinants of those values and their effects on consuming behaviors. A total of 778 students from various universities in Beijing were investigated with questionnaire survey. The main results and conclusions are as follows: (1) College students were basically satisfied with their current life and study conditions in university, and their main pressures or stresses were from their studies. They were highly motivated in the development of their academic and life careers, and also valued the importance of family and having children in the future. About 11% of the students had pressures due to less favorable financial conditions of their families. (2) Five basic consuming values were found among college students, namely, “industrious and thrifty-aimed value”, “status and brand-aimed value”, “personal and unique-oriented value”, “relation-aimed value”, and “autonomous-aimed value”. The “industrious and thrifty-aimed value” stands for the traditional consuming values in the culture, and the “status and brand-aimed value” shows an explicit tendency of consumerism. The other three consuming values had moderate relations with both of the two values. (3) There was a high negative correlation between the first two values, which showed both a general acceptance and the main trend of “industrious and thrifty-aimed value” among the students. The basic “status and brand-aimed value” was shown among 3.3% of the students. (4) The consuming values were significantly correlated with life values, indicating that consuming values could be in consistence with or be determined by basic life values. The “industrious and thrifty-aimed value” and the “autonomous-aimed value” were shown as collectivistic values, while the “status and brand-aimed value” and “relation-aimed value” were shown as individualistic values. (5) Consuming values had significant influences on consuming behaviors. (6) The demographic factors such as financial conditions of parents, children of number in family, urban-rural location of family, gender, age, and campus culture could affect consuming values and consuming behaviors of college students in both direct and indirect ways.

Prediction of GC retention values under various column temperature conditions from temperature programmed data

A numerical approach has been developed for the correlation of retention limes (total retention lime) with temperature in gas chromatography, which allows the calculation of retention parameters including retention index from data acquired under two or more different temperature program conditions. By using this procedure the optimization of temperature condition can be further achieved, especially when a temperature-programmed run is the most suitable mode in the preliminary development of an analytical method for the analysis of an unknown sample.

Preparation of monolithic silica column with strong cation-exchange stationary phase for capillary electrochromatography

A monolithic silica based strong cation-exchange stationary phase was successfully prepared for capillary electrochromatography. The monolithic silica matrix from a sol-gel process was chemically modified by treatment with 3-mercaptopropyltrimethoxysilane followed by a chemical oxidation procedure to produce the desired function. The strong cation-exchange stationary phase was characterized by its substantial and stable electroosmotic flow (EOF), and it was observed that the EOF value of the prepared column remained almost unchanged at different buffer pH values and slowly decreased with increasing phosphate concentration in the mobile phase. The monolithic silica column with strong cation-exchange stationary phase has been successfully employed in the electrochromatographic separation of beta-blockers and alkaloids extracted from traditional Chinese medicines (TCMs). The column efficiencies for the tested beta-blockers varied from 210,000 to 340,000 plates/m. A peak compression effect was observed for atenolol with the mobile phase having a low phosphate concentration.