In order to understand the kinetic characteristics of coal gas desorption based on the pulsating injection （PI）, the research experimentally studied the kinetic process of methane desorption in terms of the PI and h...In order to understand the kinetic characteristics of coal gas desorption based on the pulsating injection （PI）, the research experimentally studied the kinetic process of methane desorption in terms of the PI and hydrostatic injection （HI）. The results show that the kinetic curves of methane desorption based on PI and HI are consistent with each other, and the diffusion model can best describe the characteristics of meth- ane desorption. Initial velocity, diffusion capacity and ultimate desorption amount of methane desorption after P! are greater than those after HI, and the ultimate desorption amount increases by 16.7-39.7%. Methane decay rate over the time is less than that of the HI. The PI influences the diffusion model param- eters, and it makes the mass transfer Biot number B＇_i decrease and the mass transfer Fourier series F＇_0 increase. As a result, PI makes the methane diffusion resistance in the coal smaller, methane diffusion rate greater, mass transfer velocity faster and the disturbance range of methane concentration wider than HI. Therefore, the effect of methane desorption based on PI is better than that of HI.展开更多
Purpose. To evaluate and compare the effects of heart rate on conduction velocity in the cavotricus-pid isthmus (CTI) and septum in patients with and without typical atrial flutter (AF) using electro-anatomic mapping ...Purpose. To evaluate and compare the effects of heart rate on conduction velocity in the cavotricus-pid isthmus (CTI) and septum in patients with and without typical atrial flutter (AF) using electro-anatomic mapping (EAM) of the right atrium (RA).Methods. Ten patients(age 53+10 yrs,7M/3F)with AF and 13 patients (age 51+11 yrs, 5M/8F) with atrio-ventricular nodal reentrant tachycardia (AVNRT) underwent conventional electrophysionogical study, electro -anatomic mapping and radiofrequency ablation. Using EAMs obtained during coronary sinus pacing at pacing cycle length (PCL) 600 ms, 400 ms, and 300 ms, we evaluated conduction velocities in the CTI and septum of RA in 10 patients with AF and compared EAMs to 13 patients with AVNRT to determine whether the conduction slowing required to maintain AFL was related to changes in volume alone or altered RA electrophysiology.Results. Conduction velocities in CTI and septum were significantly slower at all PCL when AF was compared to AVNRT(P<0.05). Additionally, in the AF group, septal conduction velocities were slower at PCL 600 ms and 400 ms, but not at 300 ms compared to CTI (P<0.05). In AF, during PCL 300. conduction in CTI slowed significantly compared to PCL 600 and 400 ms such that there was no difference between CTI and septum at PCL 300.Conclusions. There is slower conduction in the septum compared to the CTI in all patients. However, in patients with AF, there is significant slowing of conduction in the CTI and septum as well as decremen-tal rate-dependent slowing of conduction in the CTI. These findings indicate that in addition to RA enlargement, changes in atrial electrophysiology distinguish AF patients from patients with AVNRT.展开更多
基金financially supported by the National Basic Research Program of China (No. 2011CB201205)the National Natural Science Foundation of China (No. 51274195)+2 种基金the Natural Science Foundation of Jiangsu Province of China (No. BK2012571)the National Major Scientific Instrument and Equipment Development Project of China (No. 2013YQ17046309)the Education Department Science and Technology Key Project of Henan Province of China (14B440007)
文摘In order to understand the kinetic characteristics of coal gas desorption based on the pulsating injection （PI）, the research experimentally studied the kinetic process of methane desorption in terms of the PI and hydrostatic injection （HI）. The results show that the kinetic curves of methane desorption based on PI and HI are consistent with each other, and the diffusion model can best describe the characteristics of meth- ane desorption. Initial velocity, diffusion capacity and ultimate desorption amount of methane desorption after P! are greater than those after HI, and the ultimate desorption amount increases by 16.7-39.7%. Methane decay rate over the time is less than that of the HI. The PI influences the diffusion model param- eters, and it makes the mass transfer Biot number B＇_i decrease and the mass transfer Fourier series F＇_0 increase. As a result, PI makes the methane diffusion resistance in the coal smaller, methane diffusion rate greater, mass transfer velocity faster and the disturbance range of methane concentration wider than HI. Therefore, the effect of methane desorption based on PI is better than that of HI.
文摘Purpose. To evaluate and compare the effects of heart rate on conduction velocity in the cavotricus-pid isthmus (CTI) and septum in patients with and without typical atrial flutter (AF) using electro-anatomic mapping (EAM) of the right atrium (RA).Methods. Ten patients(age 53+10 yrs,7M/3F)with AF and 13 patients (age 51+11 yrs, 5M/8F) with atrio-ventricular nodal reentrant tachycardia (AVNRT) underwent conventional electrophysionogical study, electro -anatomic mapping and radiofrequency ablation. Using EAMs obtained during coronary sinus pacing at pacing cycle length (PCL) 600 ms, 400 ms, and 300 ms, we evaluated conduction velocities in the CTI and septum of RA in 10 patients with AF and compared EAMs to 13 patients with AVNRT to determine whether the conduction slowing required to maintain AFL was related to changes in volume alone or altered RA electrophysiology.Results. Conduction velocities in CTI and septum were significantly slower at all PCL when AF was compared to AVNRT(P<0.05). Additionally, in the AF group, septal conduction velocities were slower at PCL 600 ms and 400 ms, but not at 300 ms compared to CTI (P<0.05). In AF, during PCL 300. conduction in CTI slowed significantly compared to PCL 600 and 400 ms such that there was no difference between CTI and septum at PCL 300.Conclusions. There is slower conduction in the septum compared to the CTI in all patients. However, in patients with AF, there is significant slowing of conduction in the CTI and septum as well as decremen-tal rate-dependent slowing of conduction in the CTI. These findings indicate that in addition to RA enlargement, changes in atrial electrophysiology distinguish AF patients from patients with AVNRT.
