Two decades ago,an important development philosophy emerged that would redefine prosperity:“Lucid waters and lush mountains are invaluable assets.”Known as the“Two Mountains”theory,it challenged the conventional t...Two decades ago,an important development philosophy emerged that would redefine prosperity:“Lucid waters and lush mountains are invaluable assets.”Known as the“Two Mountains”theory,it challenged the conventional trade-off between development and the environment by arguing that they are inseparable.展开更多
Few studies of wave propagation in layered saturated soils have been reported in the literature.In this paper,a general solution of the equation of wave motion in saturated soils,based on one kind of practical Blot...Few studies of wave propagation in layered saturated soils have been reported in the literature.In this paper,a general solution of the equation of wave motion in saturated soils,based on one kind of practical Blot's equation, was deduced by introducing wave potentials.Then exact dynamic-stiffness matrices for a poroelastic soil layer and half- space were derived,which extended Wolf's theory for an elastic layered site to the case of poroelasticity,thus resolving a fundamental problem in the field of wave propagation and soil-structure interaction in a poroelastic layered soil site.By using the integral transform method,Green's functions of horizontal and vertical uniformly distributed loads in a poroelastic layered soil site were given.Finally,the theory was verified by numerical examples and dynamic responses by comparing three different soil sites.This study has the following advantages:all parameters in the dynamic-stiffness matrices have explicitly physical meanings and the thickness of the sub-layers does not affect the precision of the calculation which is very convenient for engineering applications.The present theory can degenerate into Wolf's theory and yields numerical results approaching those for an ideal elastic layered site when porosity tends to zero.展开更多
Based on one type of practical Biot＇s equation and the dynamic-stiffness matrices ofa poroelastic soil layer and half-space, Green＇s functions were derived for unitformly distributed loads acting on an inclined line...Based on one type of practical Biot＇s equation and the dynamic-stiffness matrices ofa poroelastic soil layer and half-space, Green＇s functions were derived for unitformly distributed loads acting on an inclined line in a poroelastie layered site. This analysis overcomes significant problems in wave scattering due to local soil conditions and dynamic soil-structure interaction. The Green＇s functions can be reduced to the case of an elastic layered site developed by Wolf in 1985. Parametric studies are then carried out through two example problems.展开更多
Near-fault ground motions with long-period pulses have been identified as critical in the design of structures. To aid in the representation of this special type of motion, eight simple pulses that characterize the ef...Near-fault ground motions with long-period pulses have been identified as critical in the design of structures. To aid in the representation of this special type of motion, eight simple pulses that characterize the effects of either the flingstep or forward-directivity are considered. Relationships between pulse amplitudes and velocity pulse period for different pulses are discussed. Representative ratios and peak acceleration amplification can exhibit distinctive features depending on variations in pulse duration, amplitude and the selected acceleration pulse shape. Additionally, response spectral characteristics for the equivalent pulses are identified and compared in terms of fixed PGA and PGV, respectively. Response spectra are strongly affected by the duration of pulses and the shape of the basic pulses. Finally, dynamic time history response features of a damped SDOF system subjected to pulse excitations are examined. These special aspects of pulse waveforms and their response spectra should be taken into account in the estimation of ground motions for a project site close to a fault.展开更多
In this paper, response spectral characteristics of one-, two-, and three-lobe sinusoidal acceleration pulses are investigated, and some of their basic properties are derived. Furthermore, the empirical mode decomposi...In this paper, response spectral characteristics of one-, two-, and three-lobe sinusoidal acceleration pulses are investigated, and some of their basic properties are derived. Furthermore, the empirical mode decomposition （EMD） method is utilized as an adaptive filter to decompose the near-fault pulse-like ground motions, which were recorded during the September 20, 1999, Chi-Chi earthquake. These ground motions contain distinct velocity pulses, and were decomposed into high-frequency （HF） and low-frequency （LF） components, from which the corresponding HF acceleration pulse （if existing） and LF acceleration pulse could be easily identified and detected. Finally, the identified acceleration pulses are modeled by simplified sinusoidal approximations, whose dynamic behaviors are compared to those of the original acceleration pulses as well as to those of the original HF and LF acceleration components in the context of elastic response spectra. It was demonstrated that it is just the acceleration pulses contained in the near-fault pulse-like ground motion that fundamentally dominate the special impulsive dynamic behaviors of such motion in an engineering sense. The motion thus has a greater potential to cause severe damage than the far-field ground motions, i.e. they impose high base shear demands on engineering structures as well as placing very high deformation demands on long-period structures.展开更多
Blast pressure measurements of a controlled underwater explosion in the sea were carried out.An explosive of 25-kg trinitro-toluene(TNT)equivalent was detonated,and the blast pressures were recorded by eight diferent ...Blast pressure measurements of a controlled underwater explosion in the sea were carried out.An explosive of 25-kg trinitro-toluene(TNT)equivalent was detonated,and the blast pressures were recorded by eight diferent high-performance pressure sensors that work at the nonresonant high-voltage output in adverse underwater conditions.Recorded peak pressure values are used to establish a relationship in the well-known form of empirical underwater explosion(UNDEX)loading formula.Constants of the formula are redetermined by employing the least-squares method in two diferent forms for best ftting to the measured data.The newly determined constants are found to be only slightly diferent from the generally accepted ones.展开更多
Under strong seismic excitation, a rigid block will uplift from its support and undergo rocking oscillations which may lead to （complete） overturning. Numerical and analytical solutions to this highly nonlinear vibr...Under strong seismic excitation, a rigid block will uplift from its support and undergo rocking oscillations which may lead to （complete） overturning. Numerical and analytical solutions to this highly nonlinear vibration problem are first highlighted in the paper and then utilized to demonstrate how sensitive the overturning behavior is not only to the intensity and frequency content of the base motion, but also to thc presence of strong pulses, to their detailed sequence, and even to their asymnletry. Five idealised pulses capable of representing ＂rupture-directivity＂ and ＂fling＂ affected ground motions near the fault, are utilized to this end ： the one-cycle sinus, the one-cycle cosinus, the Ricker wavelet, the truncated （T）-Ricker wavelet, and the rectangular pulse ＂Overturning-Acceleration Amplification＂ and ＂Rotation＂ spectra are introduced and presented. Artificial neural network modeling is then developed as an alternative numerical solution. The neural network analysis leads to closed-form expressions for predicting the overturning failure or survival of a rigid block, as a function of its geometric properties and the characteristics of the excitation time history. The capability of the developed neural network modeling is validated through comparisons with the numerical solution. The derived analytical expressions could also serve as a tool for assessing the destructiveness of near-fault ground motions, for structures sensitive to rocking with foundation uplift.展开更多
A new approach to reducing the seismic response of spatial structures with magneto-theological （MR） dampers is presented in this paper. The Genetic Algorithm with small populations （μGA） is used to optimize the c...A new approach to reducing the seismic response of spatial structures with magneto-theological （MR） dampers is presented in this paper. The Genetic Algorithm with small populations （μGA） is used to optimize the control for the MR dampers to reduce structural vibration, which is difficult to achieve using classical optimal control. The advantages of μGA are the use of global properties and that fewer conditions are required to obtain the optimal function. Numerical results demonstrate the effectiveness of the proposed method in reducing the seismic response of structures.展开更多
The computation of the representative ground motions,to be used as input for the dynamic analyses of a struc- ture at a particular site,can be approached by several methods.The choice of the approach depends on two fa...The computation of the representative ground motions,to be used as input for the dynamic analyses of a struc- ture at a particular site,can be approached by several methods.The choice of the approach depends on two factors:the da- ta available and the type of problem to be solved.This paper reports the experience of the authors in approaching a specific case study:the Southern Memnon Colossus,located in Luxor,Egypt.The results are of interest when the hazard analysis estimation in developing countries and the safeguard of cultural heritage are concerned.Monuments have to be treated as important structures,due to their historical and economical value.Hence,standard procedures of probabilistic seismic haz- ard analysis for the seismic classification of common buildings have to be disregarded.On the other hand,the consequences of the collapse of a monument are not comparable to those related to structures such as nuclear power plants and large dams, for which the deterministic seismic hazard analysis provides a straightforward framework for evaluation of the worst case ground motions.An'intermediate'approach,which requites a lower amount of input data with respect to the deterministic one,is adopted.Its stochastic component can eapture significant eharacteristics of earthquakes,primarily the frequency contents which depend on the magnitude(often referred to as the earthquake scaling law).展开更多
Nelson pointed out that the wave breaking criterion( H/d)(b) for gentle slopes( i < 1/100), in which H is the wave height and d is the water depth at the breaking point, is smaller than that for beach slopes of i &...Nelson pointed out that the wave breaking criterion( H/d)(b) for gentle slopes( i < 1/100), in which H is the wave height and d is the water depth at the breaking point, is smaller than that for beach slopes of i > 1/100, i. e., the value oft H/d)(b) for gentle slopes may be smaller than 0.6. Goda indicated that the wave breaking criterion given by himself is a result based on theoretical study, so it should be also correct and can be used for gentle beaches, i.e., the value of(H/d)(b) for gentle slopes may be still larger than 0.7. By use of high order nonlinear wave theory, this problem is analyzed in this study and the reason why there is a large difference between different studies is explained. Moreover, the bottom energy loss during wave propagation is considered and the critical slope for the absence of wave breaking is also analyzed.展开更多
This study was carried out in the Health districts of Kayanza and Gahombo. Its aim was to assess the nutritional status and associated factors of infants aged between 6 and 23 months. This descriptive and cross-sectio...This study was carried out in the Health districts of Kayanza and Gahombo. Its aim was to assess the nutritional status and associated factors of infants aged between 6 and 23 months. This descriptive and cross-sectional study was carried out in the health centers of the action zone during medical consultations in community medicine from 13 to 22 February 2023. For this purpose, 53.0% of a sample of 398 mothers of infants aged 6 - 23 months were male, and the most represented age group was 12 - 23 months with 53.8%. Mothers were asked about the diet of their children. All the children involved in this study were vaccinated, whereas 99.2% were given vitamin A supplements. The most frequent illnesses in this age group were acute respiratory infection (ARI) (73.4%), fever (66.6%), diarrhea (53.8%), and vomiting (40.5%). Analysis of nutritional status showed that infants had severe (8.3%) and moderate (70.4%) acute malnutrition. Factors associated with infant nutritional status comprised the occupation of mother (P = 0.009), level of education of mother (P = 0.0625), and prolonged diarrhea (P = 0.004). To remedy this problem, concrete nutritional and educational interventions are needed to promote optimal infant nutrition during the first two years of life.展开更多
By means of a three-dimensional meteorological model(MM5)and a chemical model,the distributions of tropospheric ozone and its precursors over China have been simulated in summer and winter time,16—18 August 1994 and ...By means of a three-dimensional meteorological model(MM5)and a chemical model,the distributions of tropospheric ozone and its precursors over China have been simulated in summer and winter time,16—18 August 1994 and 7—9 January 1995.The distribution of ozone over the Tibetan Plateau in summer time is deeply discussed.The simulated results indicate that the distributions of surface ozone and NO_x are in good agreement with observed results,and human activities and photochemical reactions are the main factors controlling the surface ozone and NO_x concentrations.In addition,higher ozone concentrations are coincided with the air convergence, and the lower concentrations are related to the air divergence.In summer,over the Tibetan Plateau the strong flow convergence results in higher ozone concentrations in the lower troposphere:and the strong flow divergence results in lower ozone concentrations in the upper troposphere.In winter time ozone concentrations show Iarge-scale characteristics controlled by westerly flow,and in the jet area they are lower than those outside the jet.展开更多
The coordination field perturbation matrix element expressions about D2-field of the terms 2S+1Lf (J=0 - 8 and 7=1/2 - 15/2) with fN (N=1 -13) configuration have been derived The concrete forms of the DSCPCF parameter...The coordination field perturbation matrix element expressions about D2-field of the terms 2S+1Lf (J=0 - 8 and 7=1/2 - 15/2) with fN (N=1 -13) configuration have been derived The concrete forms of the DSCPCF parameters Akm in the dihedral field (D2, C2v) for various ligand numbers (5 -12) and their reducing behavior in the higher symmetry fields (D4, C4v, D2d, D4d, D2k, D4h and Oh) are discussed with the double sphere coordination point charge field (DSCPCF) model and the irreducible operator tensor method. Besides, the corresponding computational schemes have been developed and the computer program DSF.D has been compiled, which is applicable for the spectral analysis of the rare earth ion complexes with arbitrary ligand numbers in the dihedral, tetragonal and cubical symmetry fields.展开更多
An updated version of the Regional Acid Deposition Model(RADM)driven by meteorological fields derived from Chinese Regional Climate Model(CRegCM)is used to simulate seasonal variation of tropospheric ozone over the ea...An updated version of the Regional Acid Deposition Model(RADM)driven by meteorological fields derived from Chinese Regional Climate Model(CRegCM)is used to simulate seasonal variation of tropospheric ozone over the eastern China.The results show that: (1)Peak O_3 concentration moves from south China to north China responding to the changing of solar perpendicular incidence point from south to north.When solar perpendicular incidence point moves from north to south,so does the peak O_3 concentration. (2)In the eastern China.the highest O_3 month-average concentration appears in July.the lowest in January and the medium in April and October.The pattern mainly depends on the solar radiation,the concentration of O_3 precursors NO_x and NMHC and the ratio of NMHC/NO_x. (3)Daily variations of O_3 over the eastern China are clear.Namely,O_3 concentrations rise with the sun rising and the maximums appear at noon.then O_3 concentrations decrease.The highest daily variation range of O_3 appears in summer(40×10^(-9) in volume fraction)and the lowest in winter(20× 10^(-9) in volume fraction). (4)Daily variations of O_3 over the western China are not clear.The daily variation range of O_3 is less than 10×10^(-9) in volume fraction.展开更多
Modular methods based on the use of prefabricated structures are increasingly popular for construction projects as they contribute to sustainability by reducing waste and maintenance costs as well as improving time ef...Modular methods based on the use of prefabricated structures are increasingly popular for construction projects as they contribute to sustainability by reducing waste and maintenance costs as well as improving time efficiency.For short-term international events,the use of relocatable modular buildings is a potential solution to the problem of“White Elephant”structures built specially for the events that serve no useful purpose once the event is over.This paper focuses on a representative relocatable modular project created for the 2018 Winter Olympic Games in South Korea using a single case study approach to develop an in-depth understanding of the advantages and disadvantages of relocatable modular construction from a practitioner’s perspective and examine how this approach supports sustainability and the Olympic legacy.Important considerations are identified for each of the five main stages:1)planning,2)design and engineering,3)manufacturing,4)construction and 5)disassembly and reconstruction.These findings show how the use of relocatable modular facilities can be a useful approach for international events.展开更多
文摘Two decades ago,an important development philosophy emerged that would redefine prosperity:“Lucid waters and lush mountains are invaluable assets.”Known as the“Two Mountains”theory,it challenged the conventional trade-off between development and the environment by arguing that they are inseparable.
基金National Natural Science Foundation of China Under Grant No.50378063
文摘Few studies of wave propagation in layered saturated soils have been reported in the literature.In this paper,a general solution of the equation of wave motion in saturated soils,based on one kind of practical Blot's equation, was deduced by introducing wave potentials.Then exact dynamic-stiffness matrices for a poroelastic soil layer and half- space were derived,which extended Wolf's theory for an elastic layered site to the case of poroelasticity,thus resolving a fundamental problem in the field of wave propagation and soil-structure interaction in a poroelastic layered soil site.By using the integral transform method,Green's functions of horizontal and vertical uniformly distributed loads in a poroelastic layered soil site were given.Finally,the theory was verified by numerical examples and dynamic responses by comparing three different soil sites.This study has the following advantages:all parameters in the dynamic-stiffness matrices have explicitly physical meanings and the thickness of the sub-layers does not affect the precision of the calculation which is very convenient for engineering applications.The present theory can degenerate into Wolf's theory and yields numerical results approaching those for an ideal elastic layered site when porosity tends to zero.
基金National Natural Science Foundation of China Under Grant No.50378063
文摘Based on one type of practical Biot＇s equation and the dynamic-stiffness matrices ofa poroelastic soil layer and half-space, Green＇s functions were derived for unitformly distributed loads acting on an inclined line in a poroelastie layered site. This analysis overcomes significant problems in wave scattering due to local soil conditions and dynamic soil-structure interaction. The Green＇s functions can be reduced to the case of an elastic layered site developed by Wolf in 1985. Parametric studies are then carried out through two example problems.
基金Supported by: China Natural Science Foundation of International (Regional) Cooperative Research Program Under Grant No. 50420120133 Heilongjiang Natural Science Foundation Under Grant No. ZGJ03-03 The Research Fund for the Doctoral Program of Higher Education of China Under Grant No. 20030213042
文摘Near-fault ground motions with long-period pulses have been identified as critical in the design of structures. To aid in the representation of this special type of motion, eight simple pulses that characterize the effects of either the flingstep or forward-directivity are considered. Relationships between pulse amplitudes and velocity pulse period for different pulses are discussed. Representative ratios and peak acceleration amplification can exhibit distinctive features depending on variations in pulse duration, amplitude and the selected acceleration pulse shape. Additionally, response spectral characteristics for the equivalent pulses are identified and compared in terms of fixed PGA and PGV, respectively. Response spectra are strongly affected by the duration of pulses and the shape of the basic pulses. Finally, dynamic time history response features of a damped SDOF system subjected to pulse excitations are examined. These special aspects of pulse waveforms and their response spectra should be taken into account in the estimation of ground motions for a project site close to a fault.
基金Natural Science Foundation of China Under Grant No. 50278090
文摘In this paper, response spectral characteristics of one-, two-, and three-lobe sinusoidal acceleration pulses are investigated, and some of their basic properties are derived. Furthermore, the empirical mode decomposition （EMD） method is utilized as an adaptive filter to decompose the near-fault pulse-like ground motions, which were recorded during the September 20, 1999, Chi-Chi earthquake. These ground motions contain distinct velocity pulses, and were decomposed into high-frequency （HF） and low-frequency （LF） components, from which the corresponding HF acceleration pulse （if existing） and LF acceleration pulse could be easily identified and detected. Finally, the identified acceleration pulses are modeled by simplified sinusoidal approximations, whose dynamic behaviors are compared to those of the original acceleration pulses as well as to those of the original HF and LF acceleration components in the context of elastic response spectra. It was demonstrated that it is just the acceleration pulses contained in the near-fault pulse-like ground motion that fundamentally dominate the special impulsive dynamic behaviors of such motion in an engineering sense. The motion thus has a greater potential to cause severe damage than the far-field ground motions, i.e. they impose high base shear demands on engineering structures as well as placing very high deformation demands on long-period structures.
文摘Blast pressure measurements of a controlled underwater explosion in the sea were carried out.An explosive of 25-kg trinitro-toluene(TNT)equivalent was detonated,and the blast pressures were recorded by eight diferent high-performance pressure sensors that work at the nonresonant high-voltage output in adverse underwater conditions.Recorded peak pressure values are used to establish a relationship in the well-known form of empirical underwater explosion(UNDEX)loading formula.Constants of the formula are redetermined by employing the least-squares method in two diferent forms for best ftting to the measured data.The newly determined constants are found to be only slightly diferent from the generally accepted ones.
文摘Under strong seismic excitation, a rigid block will uplift from its support and undergo rocking oscillations which may lead to （complete） overturning. Numerical and analytical solutions to this highly nonlinear vibration problem are first highlighted in the paper and then utilized to demonstrate how sensitive the overturning behavior is not only to the intensity and frequency content of the base motion, but also to thc presence of strong pulses, to their detailed sequence, and even to their asymnletry. Five idealised pulses capable of representing ＂rupture-directivity＂ and ＂fling＂ affected ground motions near the fault, are utilized to this end ： the one-cycle sinus, the one-cycle cosinus, the Ricker wavelet, the truncated （T）-Ricker wavelet, and the rectangular pulse ＂Overturning-Acceleration Amplification＂ and ＂Rotation＂ spectra are introduced and presented. Artificial neural network modeling is then developed as an alternative numerical solution. The neural network analysis leads to closed-form expressions for predicting the overturning failure or survival of a rigid block, as a function of its geometric properties and the characteristics of the excitation time history. The capability of the developed neural network modeling is validated through comparisons with the numerical solution. The derived analytical expressions could also serve as a tool for assessing the destructiveness of near-fault ground motions, for structures sensitive to rocking with foundation uplift.
基金the Outstanding Youth Science Foundation of the National Natural Science Foundation of China Under Grant No. 50025823
文摘A new approach to reducing the seismic response of spatial structures with magneto-theological （MR） dampers is presented in this paper. The Genetic Algorithm with small populations （μGA） is used to optimize the control for the MR dampers to reduce structural vibration, which is difficult to achieve using classical optimal control. The advantages of μGA are the use of global properties and that fewer conditions are required to obtain the optimal function. Numerical results demonstrate the effectiveness of the proposed method in reducing the seismic response of structures.
文摘The computation of the representative ground motions,to be used as input for the dynamic analyses of a struc- ture at a particular site,can be approached by several methods.The choice of the approach depends on two factors:the da- ta available and the type of problem to be solved.This paper reports the experience of the authors in approaching a specific case study:the Southern Memnon Colossus,located in Luxor,Egypt.The results are of interest when the hazard analysis estimation in developing countries and the safeguard of cultural heritage are concerned.Monuments have to be treated as important structures,due to their historical and economical value.Hence,standard procedures of probabilistic seismic haz- ard analysis for the seismic classification of common buildings have to be disregarded.On the other hand,the consequences of the collapse of a monument are not comparable to those related to structures such as nuclear power plants and large dams, for which the deterministic seismic hazard analysis provides a straightforward framework for evaluation of the worst case ground motions.An'intermediate'approach,which requites a lower amount of input data with respect to the deterministic one,is adopted.Its stochastic component can eapture significant eharacteristics of earthquakes,primarily the frequency contents which depend on the magnitude(often referred to as the earthquake scaling law).
基金National Natural Science Foundation of China(Grant No.49876026)Foundation for Development of Engineering Technical Code of the Ministry of Communications of China
文摘Nelson pointed out that the wave breaking criterion( H/d)(b) for gentle slopes( i < 1/100), in which H is the wave height and d is the water depth at the breaking point, is smaller than that for beach slopes of i > 1/100, i. e., the value oft H/d)(b) for gentle slopes may be smaller than 0.6. Goda indicated that the wave breaking criterion given by himself is a result based on theoretical study, so it should be also correct and can be used for gentle beaches, i.e., the value of(H/d)(b) for gentle slopes may be still larger than 0.7. By use of high order nonlinear wave theory, this problem is analyzed in this study and the reason why there is a large difference between different studies is explained. Moreover, the bottom energy loss during wave propagation is considered and the critical slope for the absence of wave breaking is also analyzed.
文摘This study was carried out in the Health districts of Kayanza and Gahombo. Its aim was to assess the nutritional status and associated factors of infants aged between 6 and 23 months. This descriptive and cross-sectional study was carried out in the health centers of the action zone during medical consultations in community medicine from 13 to 22 February 2023. For this purpose, 53.0% of a sample of 398 mothers of infants aged 6 - 23 months were male, and the most represented age group was 12 - 23 months with 53.8%. Mothers were asked about the diet of their children. All the children involved in this study were vaccinated, whereas 99.2% were given vitamin A supplements. The most frequent illnesses in this age group were acute respiratory infection (ARI) (73.4%), fever (66.6%), diarrhea (53.8%), and vomiting (40.5%). Analysis of nutritional status showed that infants had severe (8.3%) and moderate (70.4%) acute malnutrition. Factors associated with infant nutritional status comprised the occupation of mother (P = 0.009), level of education of mother (P = 0.0625), and prolonged diarrhea (P = 0.004). To remedy this problem, concrete nutritional and educational interventions are needed to promote optimal infant nutrition during the first two years of life.
基金National Natural Science Foundation of China under Grant 49392200.
文摘By means of a three-dimensional meteorological model(MM5)and a chemical model,the distributions of tropospheric ozone and its precursors over China have been simulated in summer and winter time,16—18 August 1994 and 7—9 January 1995.The distribution of ozone over the Tibetan Plateau in summer time is deeply discussed.The simulated results indicate that the distributions of surface ozone and NO_x are in good agreement with observed results,and human activities and photochemical reactions are the main factors controlling the surface ozone and NO_x concentrations.In addition,higher ozone concentrations are coincided with the air convergence, and the lower concentrations are related to the air divergence.In summer,over the Tibetan Plateau the strong flow convergence results in higher ozone concentrations in the lower troposphere:and the strong flow divergence results in lower ozone concentrations in the upper troposphere.In winter time ozone concentrations show Iarge-scale characteristics controlled by westerly flow,and in the jet area they are lower than those outside the jet.
基金Ph. D. student of Nanjing University, Nanjing 210008, China.
文摘The coordination field perturbation matrix element expressions about D2-field of the terms 2S+1Lf (J=0 - 8 and 7=1/2 - 15/2) with fN (N=1 -13) configuration have been derived The concrete forms of the DSCPCF parameters Akm in the dihedral field (D2, C2v) for various ligand numbers (5 -12) and their reducing behavior in the higher symmetry fields (D4, C4v, D2d, D4d, D2k, D4h and Oh) are discussed with the double sphere coordination point charge field (DSCPCF) model and the irreducible operator tensor method. Besides, the corresponding computational schemes have been developed and the computer program DSF.D has been compiled, which is applicable for the spectral analysis of the rare earth ion complexes with arbitrary ligand numbers in the dihedral, tetragonal and cubical symmetry fields.
文摘An updated version of the Regional Acid Deposition Model(RADM)driven by meteorological fields derived from Chinese Regional Climate Model(CRegCM)is used to simulate seasonal variation of tropospheric ozone over the eastern China.The results show that: (1)Peak O_3 concentration moves from south China to north China responding to the changing of solar perpendicular incidence point from south to north.When solar perpendicular incidence point moves from north to south,so does the peak O_3 concentration. (2)In the eastern China.the highest O_3 month-average concentration appears in July.the lowest in January and the medium in April and October.The pattern mainly depends on the solar radiation,the concentration of O_3 precursors NO_x and NMHC and the ratio of NMHC/NO_x. (3)Daily variations of O_3 over the eastern China are clear.Namely,O_3 concentrations rise with the sun rising and the maximums appear at noon.then O_3 concentrations decrease.The highest daily variation range of O_3 appears in summer(40×10^(-9) in volume fraction)and the lowest in winter(20× 10^(-9) in volume fraction). (4)Daily variations of O_3 over the western China are not clear.The daily variation range of O_3 is less than 10×10^(-9) in volume fraction.
基金supported by the research fund of Hanyang University(HY-2014-N)。
文摘Modular methods based on the use of prefabricated structures are increasingly popular for construction projects as they contribute to sustainability by reducing waste and maintenance costs as well as improving time efficiency.For short-term international events,the use of relocatable modular buildings is a potential solution to the problem of“White Elephant”structures built specially for the events that serve no useful purpose once the event is over.This paper focuses on a representative relocatable modular project created for the 2018 Winter Olympic Games in South Korea using a single case study approach to develop an in-depth understanding of the advantages and disadvantages of relocatable modular construction from a practitioner’s perspective and examine how this approach supports sustainability and the Olympic legacy.Important considerations are identified for each of the five main stages:1)planning,2)design and engineering,3)manufacturing,4)construction and 5)disassembly and reconstruction.These findings show how the use of relocatable modular facilities can be a useful approach for international events.
