Global Positioning System technique is widely used to monitor the deformations of all kinds of buildings and constructions. According to the characteristics of the high precise GPS deformation monitoring, the theory a...Global Positioning System technique is widely used to monitor the deformations of all kinds of buildings and constructions. According to the characteristics of the high precise GPS deformation monitoring, the theory and practice of the SSDM （Similar Single-Difference Methodology） for GPS deformation monitoring are introduced synthetically from the background, the essential mathematic model,the error sources and control measures, the monitoring schemes and the software development. Some arguments are also given in the form of reference literatures. Based on the first period observation results of the GPS monitor network, SSDM solves the monitoring points＇ deformation values at a single epoch from carder phases directly, without needing to solve baseline vectors and network adjustment. The SSDM avoids the troublesome problem of detecting and repairing cycle slips, and can be used in static and dynamic deformation monitoring. In the SSDM, the unknown parameters have no relation to the numbers of satellites. If the number of synchronous satellites between stations is not less than two, the monitoring point＇s deformation information can be solved easily.展开更多
The detecting examples using the high density resistivity method, about the evaluation of containing water characteristic from the floor rock and the height of overburden failure, were given. It expresses that the hig...The detecting examples using the high density resistivity method, about the evaluation of containing water characteristic from the floor rock and the height of overburden failure, were given. It expresses that the high density resistivity method has good effect with strong maneuverability and continuous observing section during the prevention and cure for mine water disaster. At the same time, the article pointed out that the study of space data inversion and dynamic watching technology about the high density resistivity method must be enhanced in the future because of special condition of data collecting in mine.展开更多
Using similar single-difference methodology(SSDM) to solve the deformation values of the monitoring points, there is unstability of the deformation information series, at sometimes.In order to overcome this shortcomin...Using similar single-difference methodology(SSDM) to solve the deformation values of the monitoring points, there is unstability of the deformation information series, at sometimes.In order to overcome this shortcoming, Kalman filtering algorithm for this series is established,and its correctness and validity are verified with the test data obtained on the movable platform in plane. The results show that Kalman filtering can improve the correctness, reliability and stability of the deformation information series.展开更多
Formaldehyde is the key contaminant influencing building occupants＇ health in indoor environment. In order to reduce occupants＇ exposures to formaldehyde, a newly designed photocatalytic reactor was applied in a dyn...Formaldehyde is the key contaminant influencing building occupants＇ health in indoor environment. In order to reduce occupants＇ exposures to formaldehyde, a newly designed photocatalytic reactor was applied in a dynamic HVAC （heating, ventilation and air conditioning） system. The experiments were carried out for the removal of formaldehyde present in air at low parts per million （ppm） concentrations. The initial formaldehyde concentrations were set as 1.59 ppm and 0.27 ppm respectively, based on the formaldehyde levels in the polluted places. Experimental results show that the photocatalytic reactor is effective on formaldehyde photodegradation, causes a low pressure drop, and does not make the second pollution of ozone. The kinetic anaiysis indicates that the kinetics for oxidation processes can be fitted well by a pseudo-first-order kinetic model deduced from Langmuir - Hinshelwood （L-H） model.展开更多
The purpose of this paper is to discuss the influential factors of iteration accuracy when we use iteration to determine the numerical model for predicting water yield of deep drawdown mines and calculating the ground...The purpose of this paper is to discuss the influential factors of iteration accuracy when we use iteration to determine the numerical model for predicting water yield of deep drawdown mines and calculating the groundwater level. The relationship among the calculation error of groundwater level, the pumping rate, the limit of iteration convergence error, the calculation time, and the aquifer parameters were discussed by using an ideal model. Finally, the water yield of Dianzi iron mine was predicted using the testified numerical model. It is indicated that the calculation error of groundwater level is related to the limit of iteration convergence error, the calculation time and the aquifer parameters, but not to the pumping rate and the variation of groundwater level.展开更多
Based on the analyses for the characteristics of high precise GPS defor-mation monitor,according to the spatial relationship among the satellite, base point and monitoring point a new model and its corresponding algor...Based on the analyses for the characteristics of high precise GPS defor-mation monitor,according to the spatial relationship among the satellite, base point and monitoring point a new model and its corresponding algorithm were presented to solve the monitoring point deformation directly at single epoch. In this method the carrier phases is used as the basic observations, and the initial condition is precise baseline vectors obtained in the first period observations between the base point and monitoring point. This model is called the similar single difference model (SSDM). The main error sources effecting the accuracy of deformations were analyzed briefly, the single epoch algorithm of the receiver clock offset was advanced. The numerical results of test data show that the SSDM and the single epoch algorithm of receiver clock offset advanced are reliable and correct.展开更多
A solar pond, typical double-diffusive system, is a stable heat source that can collect and store the solar energy. When the thermal stable condition is not satisfied at the interface, the upper and lower convective z...A solar pond, typical double-diffusive system, is a stable heat source that can collect and store the solar energy. When the thermal stable condition is not satisfied at the interface, the upper and lower convective zone （UCZ and LCZ） will erode the middle non-convective zone （NCZ）, resulting in a drop or even a collapse of the thermal performance of solar pond. Wind strongly affects the erosion of NCZ from the entrainment of UCZ. The double-diffusion of heat and salt plays an important role in the erosion of NCZ from the entrainment of the lower-convective zone （LCZ）. The turbidity of saline water in the pond not only could lower the thermal performance of solar pond, but have effect on the entrainment mechanism. In this paper, based on the double-diffusive model along with the wind-driven turbulent entrainment model, the effects of turbidity and external wind etc. on the thermal performance of solar pond and the entrainment mechanism are analyzed with the numerical simulation.展开更多
基金Projects 2003031709 supported by National Land and Resource Bureau Science and Technology Foundation of China and 2004KJ113 by Natural ScienceResearch Project of Education Bureau of Anhui Province
文摘Global Positioning System technique is widely used to monitor the deformations of all kinds of buildings and constructions. According to the characteristics of the high precise GPS deformation monitoring, the theory and practice of the SSDM （Similar Single-Difference Methodology） for GPS deformation monitoring are introduced synthetically from the background, the essential mathematic model,the error sources and control measures, the monitoring schemes and the software development. Some arguments are also given in the form of reference literatures. Based on the first period observation results of the GPS monitor network, SSDM solves the monitoring points＇ deformation values at a single epoch from carder phases directly, without needing to solve baseline vectors and network adjustment. The SSDM avoids the troublesome problem of detecting and repairing cycle slips, and can be used in static and dynamic deformation monitoring. In the SSDM, the unknown parameters have no relation to the numbers of satellites. If the number of synchronous satellites between stations is not less than two, the monitoring point＇s deformation information can be solved easily.
文摘The detecting examples using the high density resistivity method, about the evaluation of containing water characteristic from the floor rock and the height of overburden failure, were given. It expresses that the high density resistivity method has good effect with strong maneuverability and continuous observing section during the prevention and cure for mine water disaster. At the same time, the article pointed out that the study of space data inversion and dynamic watching technology about the high density resistivity method must be enhanced in the future because of special condition of data collecting in mine.
文摘Using similar single-difference methodology(SSDM) to solve the deformation values of the monitoring points, there is unstability of the deformation information series, at sometimes.In order to overcome this shortcoming, Kalman filtering algorithm for this series is established,and its correctness and validity are verified with the test data obtained on the movable platform in plane. The results show that Kalman filtering can improve the correctness, reliability and stability of the deformation information series.
基金This researchis financed by the Foundation against SARS of shanghai Sci-tech Committee (NK2003 006)
文摘Formaldehyde is the key contaminant influencing building occupants＇ health in indoor environment. In order to reduce occupants＇ exposures to formaldehyde, a newly designed photocatalytic reactor was applied in a dynamic HVAC （heating, ventilation and air conditioning） system. The experiments were carried out for the removal of formaldehyde present in air at low parts per million （ppm） concentrations. The initial formaldehyde concentrations were set as 1.59 ppm and 0.27 ppm respectively, based on the formaldehyde levels in the polluted places. Experimental results show that the photocatalytic reactor is effective on formaldehyde photodegradation, causes a low pressure drop, and does not make the second pollution of ozone. The kinetic anaiysis indicates that the kinetics for oxidation processes can be fitted well by a pseudo-first-order kinetic model deduced from Langmuir - Hinshelwood （L-H） model.
文摘The purpose of this paper is to discuss the influential factors of iteration accuracy when we use iteration to determine the numerical model for predicting water yield of deep drawdown mines and calculating the groundwater level. The relationship among the calculation error of groundwater level, the pumping rate, the limit of iteration convergence error, the calculation time, and the aquifer parameters were discussed by using an ideal model. Finally, the water yield of Dianzi iron mine was predicted using the testified numerical model. It is indicated that the calculation error of groundwater level is related to the limit of iteration convergence error, the calculation time and the aquifer parameters, but not to the pumping rate and the variation of groundwater level.
基金Doctor Foundation of Anhui University of Science and Technology.
文摘Based on the analyses for the characteristics of high precise GPS defor-mation monitor,according to the spatial relationship among the satellite, base point and monitoring point a new model and its corresponding algorithm were presented to solve the monitoring point deformation directly at single epoch. In this method the carrier phases is used as the basic observations, and the initial condition is precise baseline vectors obtained in the first period observations between the base point and monitoring point. This model is called the similar single difference model (SSDM). The main error sources effecting the accuracy of deformations were analyzed briefly, the single epoch algorithm of the receiver clock offset was advanced. The numerical results of test data show that the SSDM and the single epoch algorithm of receiver clock offset advanced are reliable and correct.
基金The research is supported by National Natural Science Foundation of China （Grant No.50276008）.
文摘A solar pond, typical double-diffusive system, is a stable heat source that can collect and store the solar energy. When the thermal stable condition is not satisfied at the interface, the upper and lower convective zone （UCZ and LCZ） will erode the middle non-convective zone （NCZ）, resulting in a drop or even a collapse of the thermal performance of solar pond. Wind strongly affects the erosion of NCZ from the entrainment of UCZ. The double-diffusion of heat and salt plays an important role in the erosion of NCZ from the entrainment of the lower-convective zone （LCZ）. The turbidity of saline water in the pond not only could lower the thermal performance of solar pond, but have effect on the entrainment mechanism. In this paper, based on the double-diffusive model along with the wind-driven turbulent entrainment model, the effects of turbidity and external wind etc. on the thermal performance of solar pond and the entrainment mechanism are analyzed with the numerical simulation.
