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
Portal hypertension is the main complication of cirrhosis and is defined as an hepatic venous pressure gradient （HVPG） of more than 5 mmHg. Clinically significant portal hypertension is defined as HVPG of 10 mmHg or...Portal hypertension is the main complication of cirrhosis and is defined as an hepatic venous pressure gradient （HVPG） of more than 5 mmHg. Clinically significant portal hypertension is defined as HVPG of 10 mmHg or more. Development of gastroesophageal varices and variceal hemorrhage are the most direct consequence of portal hypertension. Over the last decades significant advancements in the field have led to standard treatment options. These clinical recommendations have evolved mostly as a result of rando.mized controlled trials and consensus conferences among experts where existing evidence has been reviewed and future goals for research and practice guidelines have been pro- posed. Management of varices/variceal hemorrhage is based on the clinical stage of portal hypertension. No specific treatment has shown to prevent the formation of varices. Prevention of first variceal hemorrhage depends on the size/characteristics of varices. In patients with small varices and high risk of bleeding, nonselective β-blockers are recommended, while patients with medium/large varices can be treated with either β-blockers or esophageal band ligation. Standard ofcare for acute variceal hemorrhage consists of vasoacrive drugs, endoscopic band ligation and antibiotics prophylaxis. Transjugular intrahepatic portosystemic shunt （TIPS） is reserved for those who fail standard of care or for patients who are likely to fail （＂early TIPS＂）. Prevention of recurrent variceal hemorrhage consists of the combination of β-blockers and endoscopic band ligation.展开更多
A fixed artificial source(greater than 200 kW) was used and the source location was selected at a high resistivity region to ensure high emission efficiency. Some publications used the "earth-ionosphere" mod...A fixed artificial source(greater than 200 kW) was used and the source location was selected at a high resistivity region to ensure high emission efficiency. Some publications used the "earth-ionosphere" mode in modeling the electromagnetic(EM) fields with the offset up to a thousand kilometer, and such EM fields still have a signal/noise ratio of 10-20 dB. This means that a new EM method with fixed source is feasible, but in their calculation, the displacement in air was neglected. In this work, some three-layer modeling results were presented to illustrate the basic EM fields' characteristics in the near, far and waveguide areas under "earth-ionosphere" mode, and a standard is given to distinguish the boundary of near, far and waveguide areas. Due to the influence of the ionosphere and displacement current in the air, the "earth-ionosphere" mode EM fields have an extra waveguide zone, where the fields' behavior is very different from that of the far field zone.展开更多
Numerical analyses of earthquake effects on the deformation, stability, and load transfer of a slope covered by deposits are traditionally based on the assumption that the slope is a continuum. It would be problem...Numerical analyses of earthquake effects on the deformation, stability, and load transfer of a slope covered by deposits are traditionally based on the assumption that the slope is a continuum. It would be problematic, however, to extend these approaches to the simulation of the slide, collapse and disintegration of the deposits under seismic loading. Contrary to this, a discrete element method （DEM） provides a means to consider large displacement and rotation of the non-continuum. To take the advantages of both methods of continuum and non- continuum analyses, seismic responses of a slope covered by deposits are studied by coupling a twodimensional （a-D） finite difference method and a 2-D DEM, with the bedrock being modelled by the finite difference grids and the deposits being represented by disks. A smooth transition across the boundaries of the continuous/discontinuous domains is obtained by imposing the compatibility condition and equilibrium condition along their interfaces. In the course of computation, the same time-step value is chosen for both continuous and discontinuous domains. The free-field boundaries are adopted for lateral grids of bedrock domain to eliminate the radiation damping effect. When the static equilibrium under gravity load is obtained, dynamic calculation begins under excitation of the seismic wave input from the continuum model bottom. In this way, responses to the earthquake of a slope covered by deposits are analyzed dynamically. Combined with field monitoring data, deformation and stability of the slope are discussed. The effects of the relevant parameters of spectrum characteristic, duration, andpeak acceleration of seismic waves are further investigated and explained from the simulations.展开更多
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Portal hypertension is the main complication of cirrhosis and is defined as an hepatic venous pressure gradient （HVPG） of more than 5 mmHg. Clinically significant portal hypertension is defined as HVPG of 10 mmHg or more. Development of gastroesophageal varices and variceal hemorrhage are the most direct consequence of portal hypertension. Over the last decades significant advancements in the field have led to standard treatment options. These clinical recommendations have evolved mostly as a result of rando.mized controlled trials and consensus conferences among experts where existing evidence has been reviewed and future goals for research and practice guidelines have been pro- posed. Management of varices/variceal hemorrhage is based on the clinical stage of portal hypertension. No specific treatment has shown to prevent the formation of varices. Prevention of first variceal hemorrhage depends on the size/characteristics of varices. In patients with small varices and high risk of bleeding, nonselective β-blockers are recommended, while patients with medium/large varices can be treated with either β-blockers or esophageal band ligation. Standard ofcare for acute variceal hemorrhage consists of vasoacrive drugs, endoscopic band ligation and antibiotics prophylaxis. Transjugular intrahepatic portosystemic shunt （TIPS） is reserved for those who fail standard of care or for patients who are likely to fail （＂early TIPS＂）. Prevention of recurrent variceal hemorrhage consists of the combination of β-blockers and endoscopic band ligation.
基金Projects(41204054,41541036,41604111)supported by the National Natural Science Foundation of China
文摘A fixed artificial source(greater than 200 kW) was used and the source location was selected at a high resistivity region to ensure high emission efficiency. Some publications used the "earth-ionosphere" mode in modeling the electromagnetic(EM) fields with the offset up to a thousand kilometer, and such EM fields still have a signal/noise ratio of 10-20 dB. This means that a new EM method with fixed source is feasible, but in their calculation, the displacement in air was neglected. In this work, some three-layer modeling results were presented to illustrate the basic EM fields' characteristics in the near, far and waveguide areas under "earth-ionosphere" mode, and a standard is given to distinguish the boundary of near, far and waveguide areas. Due to the influence of the ionosphere and displacement current in the air, the "earth-ionosphere" mode EM fields have an extra waveguide zone, where the fields' behavior is very different from that of the far field zone.
基金the National Basic Research Program of China (Grant No. 2008CB425802)
文摘Numerical analyses of earthquake effects on the deformation, stability, and load transfer of a slope covered by deposits are traditionally based on the assumption that the slope is a continuum. It would be problematic, however, to extend these approaches to the simulation of the slide, collapse and disintegration of the deposits under seismic loading. Contrary to this, a discrete element method （DEM） provides a means to consider large displacement and rotation of the non-continuum. To take the advantages of both methods of continuum and non- continuum analyses, seismic responses of a slope covered by deposits are studied by coupling a twodimensional （a-D） finite difference method and a 2-D DEM, with the bedrock being modelled by the finite difference grids and the deposits being represented by disks. A smooth transition across the boundaries of the continuous/discontinuous domains is obtained by imposing the compatibility condition and equilibrium condition along their interfaces. In the course of computation, the same time-step value is chosen for both continuous and discontinuous domains. The free-field boundaries are adopted for lateral grids of bedrock domain to eliminate the radiation damping effect. When the static equilibrium under gravity load is obtained, dynamic calculation begins under excitation of the seismic wave input from the continuum model bottom. In this way, responses to the earthquake of a slope covered by deposits are analyzed dynamically. Combined with field monitoring data, deformation and stability of the slope are discussed. The effects of the relevant parameters of spectrum characteristic, duration, andpeak acceleration of seismic waves are further investigated and explained from the simulations.
