2016 No. 4
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2016, (4): 1-10.
doi: 10.3969/j.issn.1000-5641.2016.04.001
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Abstract:
The fixed point set of the affine Weyl group $(\widetilde{A}_{2n},\widetilde{S})$ under its group automorphism $\alpha$ with $\alpha(\widetilde{S})=\widetilde{S}$ can be seen as the affine Weyl group $(\widetilde{C}_n,S)$. The restriction to $\widetilde{C}_{n}$ of the length function $\widetilde{l}_{2n}$ on $\widetilde{A}_{2n}$ can be seen as a weight function on $\widetilde{C}_{n}$. In the present paper, by studying the fixed point set of the affine Weyl group $(\widetilde{A}_{2n},\widetilde{S})$ under $\alpha$, we give the description for all the cells of the weighted Coxeter group $(\widetilde{C}_{n},\widetilde{l}_{2n})$ corresponding to the specific partition $\bf{3^32^{n-4}}$. We also prove that each left cell we considered in this paper is left-connected, verifying a conjecture of Lusztig in our case.
The fixed point set of the affine Weyl group $(\widetilde{A}_{2n},\widetilde{S})$ under its group automorphism $\alpha$ with $\alpha(\widetilde{S})=\widetilde{S}$ can be seen as the affine Weyl group $(\widetilde{C}_n,S)$. The restriction to $\widetilde{C}_{n}$ of the length function $\widetilde{l}_{2n}$ on $\widetilde{A}_{2n}$ can be seen as a weight function on $\widetilde{C}_{n}$. In the present paper, by studying the fixed point set of the affine Weyl group $(\widetilde{A}_{2n},\widetilde{S})$ under $\alpha$, we give the description for all the cells of the weighted Coxeter group $(\widetilde{C}_{n},\widetilde{l}_{2n})$ corresponding to the specific partition $\bf{3^32^{n-4}}$. We also prove that each left cell we considered in this paper is left-connected, verifying a conjecture of Lusztig in our case.
2016, (4): 11-24.
doi: 10.3969/j.issn.1000-5641.2016.04.002
Abstract:
The oscillation for certain third-order nonlinear variable delay dynamic equations with damping term and nonlinear neutral term on time scales is discussed in this article. By using the generalized Riccati transformation and inequality technique, some new oscillation criteria for the equations are established. Our results extend and improve some known results in the literature. Many of the results in this paper are new for the corresponding third-order difference equations and differential equations being as special cases. Some examples are given to illustrate the importance of our results.
The oscillation for certain third-order nonlinear variable delay dynamic equations with damping term and nonlinear neutral term on time scales is discussed in this article. By using the generalized Riccati transformation and inequality technique, some new oscillation criteria for the equations are established. Our results extend and improve some known results in the literature. Many of the results in this paper are new for the corresponding third-order difference equations and differential equations being as special cases. Some examples are given to illustrate the importance of our results.
2016, (4): 25-29.
doi: 10.3969/j.issn.1000-5641.2016.04.003
Abstract:
In this paper we classify relatively minimal, isotrivial families of curves $f: S \to \mathbb{P}^1$ of genus 1 with three singular fibers (Belyi fibrations). Assuming that these families have a section, we find that they are exactly 12 in number up to isomorphism. Moreover, as a result of this classification, we find that except one, the dimension of all other families in $\overline{\mathcal{M}}_1$ is zero.
In this paper we classify relatively minimal, isotrivial families of curves $f: S \to \mathbb{P}^1$ of genus 1 with three singular fibers (Belyi fibrations). Assuming that these families have a section, we find that they are exactly 12 in number up to isomorphism. Moreover, as a result of this classification, we find that except one, the dimension of all other families in $\overline{\mathcal{M}}_1$ is zero.
2016, (4): 30-37.
doi: 10.3969/j.issn.1000-5641.2016.04.004
Abstract:
We study the oscillatory behavior of a certain class of second-order variable delay nonlinear functional differential equations with a nonlinear neutral term in this article. By using the generalized Riccati transformation and some necessary analytic techniques, we establish two new oscillation criteria for the oscillation of the equations. In particular, the results obtained improve those presented in the literature.
We study the oscillatory behavior of a certain class of second-order variable delay nonlinear functional differential equations with a nonlinear neutral term in this article. By using the generalized Riccati transformation and some necessary analytic techniques, we establish two new oscillation criteria for the oscillation of the equations. In particular, the results obtained improve those presented in the literature.
2016, (4): 38-43.
doi: 10.3969/j.issn.1000-5641.2016.04.005
Abstract:
This article investigates various expressions for the generalized inverses of the Schur complement S = A BDC of a 2 2 block matrix M = A B C D ! under different conditions. Moreover, we give some new results for the generalized inverses of the Schur complement when M is positive semidefinite. Besides, some conclusions are obtained directly from our results.
This article investigates various expressions for the generalized inverses of the Schur complement S = A BDC of a 2 2 block matrix M = A B C D ! under different conditions. Moreover, we give some new results for the generalized inverses of the Schur complement when M is positive semidefinite. Besides, some conclusions are obtained directly from our results.
2016, (4): 44-59.
doi: 10.3969/j.issn.1000-5641.2016.04.006
Abstract:
In this paper, by applying Mawhins continuation theorem, some sufficient conditions on the existence of 2kT-periodic solutions for a kind of prescribed mean curvature Rayleigh p-Laplacian equation with delays are given. Then the existence of nontrivial homoclinic solutions for prescribed mean curvature Rayleigh p-Laplacian equation with delays is obtained. At last, an example is also given to illustrate the application of our main results.
In this paper, by applying Mawhins continuation theorem, some sufficient conditions on the existence of 2kT-periodic solutions for a kind of prescribed mean curvature Rayleigh p-Laplacian equation with delays are given. Then the existence of nontrivial homoclinic solutions for prescribed mean curvature Rayleigh p-Laplacian equation with delays is obtained. At last, an example is also given to illustrate the application of our main results.
2016, (4): 60-69.
doi: 10.3969/j.issn.1000-5641.2016.04.007
Abstract:
Quantile premium principle is one of the important premium principles in non-life insurance actuarial science, which is widely used in insurance practice. The Pareto risk model for quantile premium principle was established by introducing a class of loss function, and using some statistical techniques, and some estimates of risk premium including Bayes premium, Bayes estimate, maximum likelihood estimation and quantile estimation under the quantile premium principle were given. Furthermore, the statistical properties of these estimations were discussed. Finally, the mean error of these estimations were compared by using numerical simulation method.
Quantile premium principle is one of the important premium principles in non-life insurance actuarial science, which is widely used in insurance practice. The Pareto risk model for quantile premium principle was established by introducing a class of loss function, and using some statistical techniques, and some estimates of risk premium including Bayes premium, Bayes estimate, maximum likelihood estimation and quantile estimation under the quantile premium principle were given. Furthermore, the statistical properties of these estimations were discussed. Finally, the mean error of these estimations were compared by using numerical simulation method.
2016, (4): 70-76.
doi: 10.3969/j.issn.1000-5641.2016.04.008
Abstract:
In investigating graph graceful problem that has many applications in the real world, we discovery a new method called the appending-split method. By this new method we can construct large scale of trees having strongly (k, d)-graceful labellings, and provide the proof for the correctness of constructed (k, d)-graceful trees. Furthermore, such strongly (k, d)-graceful labellings can induce strongly odd-graceful labellings. Our new method can be easily transformed into a good algorithm that may be a theoretical guarantee for applying strongly (k, d)-graceful labellings to network.
In investigating graph graceful problem that has many applications in the real world, we discovery a new method called the appending-split method. By this new method we can construct large scale of trees having strongly (k, d)-graceful labellings, and provide the proof for the correctness of constructed (k, d)-graceful trees. Furthermore, such strongly (k, d)-graceful labellings can induce strongly odd-graceful labellings. Our new method can be easily transformed into a good algorithm that may be a theoretical guarantee for applying strongly (k, d)-graceful labellings to network.
2016, (4): 77-85.
doi: 10.3969/j.issn.1000-5641.2016.04.009
Abstract:
To take advantages of local binary patterns (LBP) and Gabor, we proposed an algorithm for face recognition based on hybrid features, using cosine similarity and principal component analysis (PCA). Four kinds of LBP and Gabor hybrid feature methods were studied and experimental results on 871 peoples nearinfrared face illustrated that the proposed method attained higher correct rate and lower false accept rate (FAR).
To take advantages of local binary patterns (LBP) and Gabor, we proposed an algorithm for face recognition based on hybrid features, using cosine similarity and principal component analysis (PCA). Four kinds of LBP and Gabor hybrid feature methods were studied and experimental results on 871 peoples nearinfrared face illustrated that the proposed method attained higher correct rate and lower false accept rate (FAR).
2016, (4): 86-95.
doi: 10.3969/j.issn.1000-5641.2016.04.010
Abstract:
Aiming at the problems that process neural network has more learning parameters, sensitive to initial value, complicated computation and difficult to converge for the gradient descent algorithm based on orthogonal basis expansion, a new process neural network based on extreme learning machine is presented in this paper. The iterative adjustment strategy is rejected in the trainning process and use Moore-Penrose to calculate the output weight matrix. In order to make up for the lack of random assignment for the extreme learning machine, the particle swarm algorthim is taken and the parameters are optimized with its global search ability. This algorthim can get the more tightly network structure and improve the model generalization ability. The model and algorthim are applied to Henon chaotic time series and sunspot prediction. The simulation resultsconfirm the validity and feasibility of the model and learning algorithm.
Aiming at the problems that process neural network has more learning parameters, sensitive to initial value, complicated computation and difficult to converge for the gradient descent algorithm based on orthogonal basis expansion, a new process neural network based on extreme learning machine is presented in this paper. The iterative adjustment strategy is rejected in the trainning process and use Moore-Penrose to calculate the output weight matrix. In order to make up for the lack of random assignment for the extreme learning machine, the particle swarm algorthim is taken and the parameters are optimized with its global search ability. This algorthim can get the more tightly network structure and improve the model generalization ability. The model and algorthim are applied to Henon chaotic time series and sunspot prediction. The simulation resultsconfirm the validity and feasibility of the model and learning algorithm.
2016, (4): 96-103.
doi: 10.3969/j.issn.1000-5641.2016.04.011
Abstract:
In order to improve the efficiency of handing operation of the containers of multiple sizes at automated container terminal,the problem of IAV (Intelligent and Autonomous Vehicle) pairing and coordinating to complete the task was studied. Multiobjective mixed integer programming model was formulated for facilitating location problem. The model aimed at minimizing makespan time,empty time and maximizing idle time. Experiments was designed to study the impact of parameter change on the characteristics of the model. Pareto analysis was carried out to verify the feasibility and effectiveness of the model, and provided automated container terminal with IAV pairing scheduling method for reference.
In order to improve the efficiency of handing operation of the containers of multiple sizes at automated container terminal,the problem of IAV (Intelligent and Autonomous Vehicle) pairing and coordinating to complete the task was studied. Multiobjective mixed integer programming model was formulated for facilitating location problem. The model aimed at minimizing makespan time,empty time and maximizing idle time. Experiments was designed to study the impact of parameter change on the characteristics of the model. Pareto analysis was carried out to verify the feasibility and effectiveness of the model, and provided automated container terminal with IAV pairing scheduling method for reference.
2016, (4): 104-110.
doi: 10.3969/j.issn.1000-5641.2016.04.012
Abstract:
Zinc tetraphenylporphyrin (ZnTPP) film on mica was prepared by vacuum thermal evaporation，and the thickness could be calibrated by single molecular layer. The photoluminescence (PL) spectra of ZnTPP film on mica gradually changed from the spectra of monomer to that of dimer as the number of molecule layers increasing. The atomic force microscopy (AFM) image showed that ZnTPP molecules on the mica surface were clustered into nanoislands. The nanoislands were further aggregated in nonvacuum environment, which might enhance the intensity of dimer fluorescence. Fluorescence lifetime showed that the decay channel ratio of dimer increased significantly in non vacuum environment.
Zinc tetraphenylporphyrin (ZnTPP) film on mica was prepared by vacuum thermal evaporation，and the thickness could be calibrated by single molecular layer. The photoluminescence (PL) spectra of ZnTPP film on mica gradually changed from the spectra of monomer to that of dimer as the number of molecule layers increasing. The atomic force microscopy (AFM) image showed that ZnTPP molecules on the mica surface were clustered into nanoislands. The nanoislands were further aggregated in nonvacuum environment, which might enhance the intensity of dimer fluorescence. Fluorescence lifetime showed that the decay channel ratio of dimer increased significantly in non vacuum environment.
2016, (4): 111-117.
doi: 10.3969/j.issn.1000-5641.2016.04.013
Abstract:
In this paper, quantum correlation in an entangled coherent state (ECS) is extensively studied with four popular quantifiers, namely, entanglement of formation (E), quantum discord (QD), measurement-induced disturbance (MID) and geometric measure of quantum discord (GQD). Besides, the influence of amplitude damping noises on the quantum correlation is treated. It is found that, E decreases faster than QD.E (QD or MID) behaves quite similarly in an asymmetric and a symmetric noisy channel. Whats more, it is obvious that the Bell state is not always more entangled than the ECS.
In this paper, quantum correlation in an entangled coherent state (ECS) is extensively studied with four popular quantifiers, namely, entanglement of formation (E), quantum discord (QD), measurement-induced disturbance (MID) and geometric measure of quantum discord (GQD). Besides, the influence of amplitude damping noises on the quantum correlation is treated. It is found that, E decreases faster than QD.E (QD or MID) behaves quite similarly in an asymmetric and a symmetric noisy channel. Whats more, it is obvious that the Bell state is not always more entangled than the ECS.
2016, (4): 118-128.
doi: 10.3969/j.issn.1000-5641.2016.04.014
Abstract:
Interconnected river system network is proposed as a new national water control strategy in the new era, thus study on the connotation and theory of interconnected river system network has become the focus of scientific research. The classification system of riverlake interconnected relationship, various kinds of dynamic flows and the material and energy interchange and the interactions between rivers and lake were discussed in this paper. And the evolution ways, patterns, the ecological functions of the riverlake interconnected system were also discussed in this paper, etc. Based on these things, the authors had defined clearly the connotation of the riverlake interconnected relationship in this paper. In riverlake interconnected system, the authors considered that there is the material and energy interchange, which is the first and foremost material and energy exchange relationship between rivers and lakes. The authors also point out that there are multiple flows between rivers and lakes, viz. material flows (water, dissolved substance, sediment, organisms, contaminants, etc.), energy flows (water level, discharge, velocity, etc.), information flows (information generated with the water flows, organisms and human activities, etc.) and value flows (shipping, power generation, drinking and irrigation, etc.). Under the disturbance of natural and human activities conditions, these flows are based on the connection of rivers and lakes, proceeding the material and energy interchange (watersediment exchange, etc.) between rivers and lakes, implementing the riverlake interactions. It is the watersediment exchange of the material and quantity interchange between rivers and lakes that is one of the approach and the direct driving forces for evolution of the riverlake interconnected relationship. The river lake interconnected relationships evolution tends to relative steady state in the end, which is an ideal dynamic balance. If any changing of whichever elements in river lake interconnected system happened, the others must occur the chain reaction, forming feedback, which affects on the function playing of the whole system, eventually will affect on preventing a flood and fighting a drought, ecological balance, resource utilization and environmental protection in a watershed. We should correctly recognize the river lake interconnected relationship of river network, which has some reference values for the construction of riverlake interconnection project and the water resources department of local governments decision.
Interconnected river system network is proposed as a new national water control strategy in the new era, thus study on the connotation and theory of interconnected river system network has become the focus of scientific research. The classification system of riverlake interconnected relationship, various kinds of dynamic flows and the material and energy interchange and the interactions between rivers and lake were discussed in this paper. And the evolution ways, patterns, the ecological functions of the riverlake interconnected system were also discussed in this paper, etc. Based on these things, the authors had defined clearly the connotation of the riverlake interconnected relationship in this paper. In riverlake interconnected system, the authors considered that there is the material and energy interchange, which is the first and foremost material and energy exchange relationship between rivers and lakes. The authors also point out that there are multiple flows between rivers and lakes, viz. material flows (water, dissolved substance, sediment, organisms, contaminants, etc.), energy flows (water level, discharge, velocity, etc.), information flows (information generated with the water flows, organisms and human activities, etc.) and value flows (shipping, power generation, drinking and irrigation, etc.). Under the disturbance of natural and human activities conditions, these flows are based on the connection of rivers and lakes, proceeding the material and energy interchange (watersediment exchange, etc.) between rivers and lakes, implementing the riverlake interactions. It is the watersediment exchange of the material and quantity interchange between rivers and lakes that is one of the approach and the direct driving forces for evolution of the riverlake interconnected relationship. The river lake interconnected relationships evolution tends to relative steady state in the end, which is an ideal dynamic balance. If any changing of whichever elements in river lake interconnected system happened, the others must occur the chain reaction, forming feedback, which affects on the function playing of the whole system, eventually will affect on preventing a flood and fighting a drought, ecological balance, resource utilization and environmental protection in a watershed. We should correctly recognize the river lake interconnected relationship of river network, which has some reference values for the construction of riverlake interconnection project and the water resources department of local governments decision.
2016, (4): 129-138.
doi: 10.3969/j.issn.1000-5641.2016.04.015
Abstract:
Using three different retrieval algorithms based on Landsat-8 thermal infrared data and meteorological data, land surface temperature (LST) of the Taihu Lake region is obtained. After comparing the values of three different algorithms with measured values, we find that the result of radiative transfer equation (RTE) is a good approximation to the measured values. When the real-time atmospheric profile is absent, general single-channel algorithm (SC) is more suitable for land surface temperature retrieval based on Landsat 8 thermal infrared data.The split window algorithm (SW) has the lowest accuracy. After analyzing the LST characteristics of different land cover based on the result of RTE, we find that built-up areas has the highest LST while water body has the lowest LST. There is a negative correlation relationship between the normalized difference vegetation index (NDVI) and the LST values, which indicates that urban green space is a key way to improve urban thermal environment and alleviate urban heat island effect. Finally, after comparing the LST results in year 2000 and 2014, we find that the heat island phenomenon of the Taihu Lake region is increasing in the past 14 years and single existent urban heat islands has gradually become coexistent heat islands now. Building land expansion is the main reason that leads to the increasing of urban heat island.
Using three different retrieval algorithms based on Landsat-8 thermal infrared data and meteorological data, land surface temperature (LST) of the Taihu Lake region is obtained. After comparing the values of three different algorithms with measured values, we find that the result of radiative transfer equation (RTE) is a good approximation to the measured values. When the real-time atmospheric profile is absent, general single-channel algorithm (SC) is more suitable for land surface temperature retrieval based on Landsat 8 thermal infrared data.The split window algorithm (SW) has the lowest accuracy. After analyzing the LST characteristics of different land cover based on the result of RTE, we find that built-up areas has the highest LST while water body has the lowest LST. There is a negative correlation relationship between the normalized difference vegetation index (NDVI) and the LST values, which indicates that urban green space is a key way to improve urban thermal environment and alleviate urban heat island effect. Finally, after comparing the LST results in year 2000 and 2014, we find that the heat island phenomenon of the Taihu Lake region is increasing in the past 14 years and single existent urban heat islands has gradually become coexistent heat islands now. Building land expansion is the main reason that leads to the increasing of urban heat island.
2016, (4): 139-149.
doi: 10.3969/j.issn.1000-5641.2016.04.016
Abstract:
Based on the ecological footprint model and the carrying capacities of water resources from 2001 to 2013 in Beijing, the ecological footprint and the carrying capacities in Shanghai at the same year were calculated and the current situation was analyzed. Furthermore, using the techniques of Support Vector Regression (SVR) in machine learning, the ecological footprints in Shanghai from 2014 to 2016 were predicted, and the possible influencing factors were discussed. The results show that the ecological footprints of water from 2001 to 2010 keep steady, while from 2011 to 2013 there are significant reductions compared with previous years. The status of water resources from 2001 to 2013 have been characterized by ecological deficit, and the annual average of difference of water resources ecological pressure index is 3.083 11, which demonstrates that the local water resources cannot be self-sufficient, so as to need transit water resources to meet the needs of normalproduction and living. In spite of the industrial structure in the optimization and economic benefits of water resources in improving, the ecological footprint of ten thousand yuan GDP and ten thousand yuan industrial GDP in Shanghai is on the decline, and the average is higher than Beijing, and therefore there is still improve space. The predicted results show that the ecological footprint from 2014 to 2016 will present a rising trend every year. The situation of water crisis will be increasingly serious, thus measures of protection of water resources and promoting the sustainable development should be put into effect.
Based on the ecological footprint model and the carrying capacities of water resources from 2001 to 2013 in Beijing, the ecological footprint and the carrying capacities in Shanghai at the same year were calculated and the current situation was analyzed. Furthermore, using the techniques of Support Vector Regression (SVR) in machine learning, the ecological footprints in Shanghai from 2014 to 2016 were predicted, and the possible influencing factors were discussed. The results show that the ecological footprints of water from 2001 to 2010 keep steady, while from 2011 to 2013 there are significant reductions compared with previous years. The status of water resources from 2001 to 2013 have been characterized by ecological deficit, and the annual average of difference of water resources ecological pressure index is 3.083 11, which demonstrates that the local water resources cannot be self-sufficient, so as to need transit water resources to meet the needs of normalproduction and living. In spite of the industrial structure in the optimization and economic benefits of water resources in improving, the ecological footprint of ten thousand yuan GDP and ten thousand yuan industrial GDP in Shanghai is on the decline, and the average is higher than Beijing, and therefore there is still improve space. The predicted results show that the ecological footprint from 2014 to 2016 will present a rising trend every year. The situation of water crisis will be increasingly serious, thus measures of protection of water resources and promoting the sustainable development should be put into effect.
2016, (4): 150-157.
doi: 10.3969/j.issn.1000-5641.2016.04.017
Abstract:
FCM is one of the most widely used fuzzy clustering methods. Being different from the distinct clustering, the fuzzy clustering provides variations of membership of entity. The variations serve as useful references for adjusting centroids and allocating clusters during and after the clustering respectively. It is a commonly used way in FCM applications to allocate a pixel according to the maximum of memberships of this pixel owns. Such hard partition will likely allocate the pixel to an inappropriate class. Therefore, a soft partition approach, called as SPFCM, has been investigated in this paper. The soft partition depends on both the dispersion degree of the memberships (represented by the standard deviation between the memberships) and the spatial dependence of pixels (indicated by the density of neighborhood pixels). There are four steps to conduct the soft partition：1) Get a membership matrix by FCM clustering. 2) Calculate the standard deviation of class membership for each pixel from the membership matrix. 3) Compute the density of neighboring elements for each class in the pixels neighbor and these elements are weighted by their membership. 4) Take the results from step 2 and 3 as references to allocate the centre pixel. To release from manual operation, some important adjustable parameters (e.g. neighborhood window size, etc.) are determined by adaptive calculation. Experiments indicate that the average area of clustering patches can be applied to derive the base number of window size for calculating the density of neighboring elements. MATLAB simulation tests show that the accuracy of allocation by SPFCM is 9% higher than that by the hard one involved with the maximum membership.
FCM is one of the most widely used fuzzy clustering methods. Being different from the distinct clustering, the fuzzy clustering provides variations of membership of entity. The variations serve as useful references for adjusting centroids and allocating clusters during and after the clustering respectively. It is a commonly used way in FCM applications to allocate a pixel according to the maximum of memberships of this pixel owns. Such hard partition will likely allocate the pixel to an inappropriate class. Therefore, a soft partition approach, called as SPFCM, has been investigated in this paper. The soft partition depends on both the dispersion degree of the memberships (represented by the standard deviation between the memberships) and the spatial dependence of pixels (indicated by the density of neighborhood pixels). There are four steps to conduct the soft partition：1) Get a membership matrix by FCM clustering. 2) Calculate the standard deviation of class membership for each pixel from the membership matrix. 3) Compute the density of neighboring elements for each class in the pixels neighbor and these elements are weighted by their membership. 4) Take the results from step 2 and 3 as references to allocate the centre pixel. To release from manual operation, some important adjustable parameters (e.g. neighborhood window size, etc.) are determined by adaptive calculation. Experiments indicate that the average area of clustering patches can be applied to derive the base number of window size for calculating the density of neighboring elements. MATLAB simulation tests show that the accuracy of allocation by SPFCM is 9% higher than that by the hard one involved with the maximum membership.
2016, (4): 158-168.
doi: 10.3969/j.issn.1000-5641.2016.04.018
Abstract:
In order to study the indication effect of magnetic properties of atmospheric dustfall on the pollution source, magnetic parameters, mineral composition, morphology and particle size were measured on atmospheric dustfall from different source region of cement factory, quartz sand factory and county seat. Results showed that dustfall mainly came from the local matter, the dustfall of quartz sand factory was monomineral with morphology of granular structure, its main component was quartz with coarse grain size and angular shape. The dustfall of cement factory was sheet and irregularly granular aggregation, its principal constituents were silicates and carbonates. The dustfall of county seat was granular and flocculent, the component was complex, whose main elements were Si!Al!Na!Ca!Fe and so on. The magnetic mineral content of dustfall changed withseasons, it was higher in winter. The magnetic mineral content of dustfall from different source region was not the same, the dustfall of county seat was the highest, its magnetic parameters can be a good indicator of pollution sources. The atmosphere pollution of quartz sand factory and cement factory was serious, their average values of monthly dustfall were far higher than county seat, but the magnetic mineral content of these two kinds of industrial dustfall was lower than county seat, and their magnetic characteristics was similar. We must combine with their mineral composition, morphology and particle size to distinguish, then set up connection.
In order to study the indication effect of magnetic properties of atmospheric dustfall on the pollution source, magnetic parameters, mineral composition, morphology and particle size were measured on atmospheric dustfall from different source region of cement factory, quartz sand factory and county seat. Results showed that dustfall mainly came from the local matter, the dustfall of quartz sand factory was monomineral with morphology of granular structure, its main component was quartz with coarse grain size and angular shape. The dustfall of cement factory was sheet and irregularly granular aggregation, its principal constituents were silicates and carbonates. The dustfall of county seat was granular and flocculent, the component was complex, whose main elements were Si!Al!Na!Ca!Fe and so on. The magnetic mineral content of dustfall changed withseasons, it was higher in winter. The magnetic mineral content of dustfall from different source region was not the same, the dustfall of county seat was the highest, its magnetic parameters can be a good indicator of pollution sources. The atmosphere pollution of quartz sand factory and cement factory was serious, their average values of monthly dustfall were far higher than county seat, but the magnetic mineral content of these two kinds of industrial dustfall was lower than county seat, and their magnetic characteristics was similar. We must combine with their mineral composition, morphology and particle size to distinguish, then set up connection.
2016, (4): 169-176.
doi: 10.3969/j.issn.1000-5641.2016.04.019
Abstract:
An investigation on the native herbs under the forest of Shanghai Green Belt was conducted in the paper. The result showed that the native herbs recorded in the study area included 111 species, 85 genera and 35 families, which accounted for 36.63%, 45.70% and 70.00% of Shanghai existing herb flora respectively. Most of the herbs belonged to monotypic or oligotypic families. On the geographical elements, the flora showed temperate characteristics and transition to subtropics; there were 7 life form types and the perennial herbs and annual herbs took similar proportion of all species recorded, which could be affected by human disturbance. The application potential of native herbs in urban green engineering were also proposed in the paper.
An investigation on the native herbs under the forest of Shanghai Green Belt was conducted in the paper. The result showed that the native herbs recorded in the study area included 111 species, 85 genera and 35 families, which accounted for 36.63%, 45.70% and 70.00% of Shanghai existing herb flora respectively. Most of the herbs belonged to monotypic or oligotypic families. On the geographical elements, the flora showed temperate characteristics and transition to subtropics; there were 7 life form types and the perennial herbs and annual herbs took similar proportion of all species recorded, which could be affected by human disturbance. The application potential of native herbs in urban green engineering were also proposed in the paper.