Chouioia cunea Yang is a natural enemy for many kinds of crop and forest pests, particularly for Hyphantria cunea Drary, which is an international quarantine pest. The experiment of rearing Chouioia cunea with Tussah ...Chouioia cunea Yang is a natural enemy for many kinds of crop and forest pests, particularly for Hyphantria cunea Drary, which is an international quarantine pest. The experiment of rearing Chouioia cunea with Tussah (Silkworm) pupa were carried out by 搕hree-cut method?and inoculating method. The results showed that three-cut method is effective way for breed-ing Chouioia cunea, with a parasitical rate of 95%. The biological characteristics and the life cycle of Chouioia cunea were ob-served and described and more hosts of Chouioia cunea were found. 揟hree-cut method?as a new technique of rearing Chouioia cunea has been put into practice.展开更多
Fracture evolution process (initiation, propagation and coalescence) of cracked rock was observed and the force- displacement curves of cracked rock were measured under uniaxial cyclic loading. The tested specimens ma...Fracture evolution process (initiation, propagation and coalescence) of cracked rock was observed and the force- displacement curves of cracked rock were measured under uniaxial cyclic loading. The tested specimens made of sandstone-like modeling material contained three pre-existing intermittent cracks with different geometrical distributions. The experimental results indicate that the fatigue deformation limit corresponding to the maximal cyclic load is equal to that of post-peak locus of static complete force?displacement curve; the fatigue deformation process can be divided into three stages: initial deformation, constant deformation rate and accelerative deformation; the time of fracture initiation, propagation and coalescence corresponds to the change of irreversible deformation.展开更多
Amman＇s land typology is characterized by hilly slopes, and this presents challenges and opportunities for architects and designers aiming at delivering sustainable buildings. The research focuses on the importance o...Amman＇s land typology is characterized by hilly slopes, and this presents challenges and opportunities for architects and designers aiming at delivering sustainable buildings. The research focuses on the importance of any site＇s given criteria, mainly its slope and topography on the delivery of sustainable buildings. Amman city consists broadly of two main types of buildings, apartment buildings and villas, by studying each type of building with regard to its environmental context on a given site in the city, the research seeks to identify the sustainable variables that site topography delimit or facilitate, using a set of attributes for each building type. The main objective of this research is to highlight the sustainable approach for building on sloped sites throughout the building project life-cycle in general, and to set a sustainability framework for designers during the initial design phase in particular. A number of case studies for both types of buildings are studied and analysed, and conclusions are given based on syntheses of available data from literature review or case analysis. At the end, the research provides a mechanism for the development of guidelines for sustainable and passive viability on preferred buildings orientation in hilly areas with regard to local climatic data.展开更多
In this paper, we prove some limit theorems for killed Brownian motion during its life time. The emphases are on quasi-stationarity and quasi-ergodicity and related problems. On one hand, using an eigenfunction expans...In this paper, we prove some limit theorems for killed Brownian motion during its life time. The emphases are on quasi-stationarity and quasi-ergodicity and related problems. On one hand, using an eigenfunction expansion for the transition density, we prove the existence and uniqueness of both quasi-stationary distribution (qsd) and mean ratio quasi-stationary distribution (mrqsd). The later is shown to be closely related to laws of large numbers (LLN) and to quasi-ergodicity. We further show that the mrqsd is the unique stationary distribution of a certain limiting ergodic diffusion process of the BM conditioned on not having been killed. We also show that a phase transition occurs from mrqsd to qsd. On the other hand, we study the large deviation behavior related to the above problems. A key observation is that the mrqsd is the unique minimum of certain large deviation rate function. We further prove that the limiting diffusion process also satisfies a large deviation principle with the rate function attaining its unique minimum at the mrqsd. These give interpretations of the mrqsd from different points of view, and establish some intrinsic connections among the above topics. Some general results concerning Yaglom limit, moment convergence and LLN are also obtained.展开更多
文摘Chouioia cunea Yang is a natural enemy for many kinds of crop and forest pests, particularly for Hyphantria cunea Drary, which is an international quarantine pest. The experiment of rearing Chouioia cunea with Tussah (Silkworm) pupa were carried out by 搕hree-cut method?and inoculating method. The results showed that three-cut method is effective way for breed-ing Chouioia cunea, with a parasitical rate of 95%. The biological characteristics and the life cycle of Chouioia cunea were ob-served and described and more hosts of Chouioia cunea were found. 揟hree-cut method?as a new technique of rearing Chouioia cunea has been put into practice.
基金Projects(50479023, 50708034) supported by the National Natural Science Foundation of ChinaProject(20070532069) supported by Specialized Research Fund for the Doctoral Program of Higher Education+1 种基金Project (20060400263) supported by China Postdoctoral Science FoundationProject(2007RS4031) supported by Provincial Science and Technology Plan of Hunan
文摘Fracture evolution process (initiation, propagation and coalescence) of cracked rock was observed and the force- displacement curves of cracked rock were measured under uniaxial cyclic loading. The tested specimens made of sandstone-like modeling material contained three pre-existing intermittent cracks with different geometrical distributions. The experimental results indicate that the fatigue deformation limit corresponding to the maximal cyclic load is equal to that of post-peak locus of static complete force?displacement curve; the fatigue deformation process can be divided into three stages: initial deformation, constant deformation rate and accelerative deformation; the time of fracture initiation, propagation and coalescence corresponds to the change of irreversible deformation.
文摘Amman＇s land typology is characterized by hilly slopes, and this presents challenges and opportunities for architects and designers aiming at delivering sustainable buildings. The research focuses on the importance of any site＇s given criteria, mainly its slope and topography on the delivery of sustainable buildings. Amman city consists broadly of two main types of buildings, apartment buildings and villas, by studying each type of building with regard to its environmental context on a given site in the city, the research seeks to identify the sustainable variables that site topography delimit or facilitate, using a set of attributes for each building type. The main objective of this research is to highlight the sustainable approach for building on sloped sites throughout the building project life-cycle in general, and to set a sustainability framework for designers during the initial design phase in particular. A number of case studies for both types of buildings are studied and analysed, and conclusions are given based on syntheses of available data from literature review or case analysis. At the end, the research provides a mechanism for the development of guidelines for sustainable and passive viability on preferred buildings orientation in hilly areas with regard to local climatic data.
基金supported by National Natural Science Foundation of China(Grant No. 10971253)
文摘In this paper, we prove some limit theorems for killed Brownian motion during its life time. The emphases are on quasi-stationarity and quasi-ergodicity and related problems. On one hand, using an eigenfunction expansion for the transition density, we prove the existence and uniqueness of both quasi-stationary distribution (qsd) and mean ratio quasi-stationary distribution (mrqsd). The later is shown to be closely related to laws of large numbers (LLN) and to quasi-ergodicity. We further show that the mrqsd is the unique stationary distribution of a certain limiting ergodic diffusion process of the BM conditioned on not having been killed. We also show that a phase transition occurs from mrqsd to qsd. On the other hand, we study the large deviation behavior related to the above problems. A key observation is that the mrqsd is the unique minimum of certain large deviation rate function. We further prove that the limiting diffusion process also satisfies a large deviation principle with the rate function attaining its unique minimum at the mrqsd. These give interpretations of the mrqsd from different points of view, and establish some intrinsic connections among the above topics. Some general results concerning Yaglom limit, moment convergence and LLN are also obtained.
