Silicon fines, boron acid solid powders and microfine SiO 2 as sintering agents were incorporated into Al 2O 3-SiC-C ramming mix in order to investigated their effects on the microstructure, mechanical properties a...Silicon fines, boron acid solid powders and microfine SiO 2 as sintering agents were incorporated into Al 2O 3-SiC-C ramming mix in order to investigated their effects on the microstructure, mechanical properties and sintering behavior of the ramming mix. Results show that all the three agents could improved both densification and mehanical properties markedly, compared to that of non-agent specimens and the effect of the composite of boron acid solid powders and microfine SiO 2 is the best. The oxidation resistance increased with the addition of agents, which is supported by densification. Microstructures showed that agent powders could fill pores or produce liquid phases at high temperature, therefore, improve the sintering of the ramming mix.展开更多
The aim of this experimental work was to investigate the Theological and adhesive performance of gunning mix suspensions. The results of rheological tests indicate that: the rheological curve of gunning mix bonded by ...The aim of this experimental work was to investigate the Theological and adhesive performance of gunning mix suspensions. The results of rheological tests indicate that: the rheological curve of gunning mix bonded by high-alumina cement (HACG) is Bingham type ; the rheological curve of low cement gunning mix (LCG) bonded by mi-crosilica is characterized by pseudo-plasticity fluid with yielding stress ; and the rheological property of low-cement gunning mix bonded by microsilica is proved to be better than that of gunning mix bonded by cement. Meanwhile as indicated by the adhesive tests: the better the rheological properties of gunning mix suspension , the better the repair effect would be.展开更多
Atrial fibrillation (AF) is the most common sustained arrhythmia encounteredin clinical practice.1 Its incidence increases with age and the presence of structural heartdisease. It is a major cause of stroke, especiall...Atrial fibrillation (AF) is the most common sustained arrhythmia encounteredin clinical practice.1 Its incidence increases with age and the presence of structural heartdisease. It is a major cause of stroke, especially in the elderly. It has been shown thatangiotensin converting enzyme inhibitor (ACEI) can reduce the incidence of AF after acute myocardialinfarction.2 Several studies have shown that activation of the rennin-angiotensin system isassociated with the mechanisms of AF. Irbesartan is a long-acting angiotensin II type 1 receptorantagonist used widely in the treatment of hypertension.3 In recent years, it has been demonstratedthat patients treated with amiodarone plus irbesartan had a lower rate of recurrence of atrialfibrillation than did patients treated with amiodarone alone.4 These findings suggest that theinhibition of angiotensin II may prevent AF, but its underlying electrophysiological mechanisms areobscure. The purpose of this study is to investigate the effects of irbesartan on atrial cellelectrophysiology.展开更多
文摘Silicon fines, boron acid solid powders and microfine SiO 2 as sintering agents were incorporated into Al 2O 3-SiC-C ramming mix in order to investigated their effects on the microstructure, mechanical properties and sintering behavior of the ramming mix. Results show that all the three agents could improved both densification and mehanical properties markedly, compared to that of non-agent specimens and the effect of the composite of boron acid solid powders and microfine SiO 2 is the best. The oxidation resistance increased with the addition of agents, which is supported by densification. Microstructures showed that agent powders could fill pores or produce liquid phases at high temperature, therefore, improve the sintering of the ramming mix.
文摘The aim of this experimental work was to investigate the Theological and adhesive performance of gunning mix suspensions. The results of rheological tests indicate that: the rheological curve of gunning mix bonded by high-alumina cement (HACG) is Bingham type ; the rheological curve of low cement gunning mix (LCG) bonded by mi-crosilica is characterized by pseudo-plasticity fluid with yielding stress ; and the rheological property of low-cement gunning mix bonded by microsilica is proved to be better than that of gunning mix bonded by cement. Meanwhile as indicated by the adhesive tests: the better the rheological properties of gunning mix suspension , the better the repair effect would be.
文摘Atrial fibrillation (AF) is the most common sustained arrhythmia encounteredin clinical practice.1 Its incidence increases with age and the presence of structural heartdisease. It is a major cause of stroke, especially in the elderly. It has been shown thatangiotensin converting enzyme inhibitor (ACEI) can reduce the incidence of AF after acute myocardialinfarction.2 Several studies have shown that activation of the rennin-angiotensin system isassociated with the mechanisms of AF. Irbesartan is a long-acting angiotensin II type 1 receptorantagonist used widely in the treatment of hypertension.3 In recent years, it has been demonstratedthat patients treated with amiodarone plus irbesartan had a lower rate of recurrence of atrialfibrillation than did patients treated with amiodarone alone.4 These findings suggest that theinhibition of angiotensin II may prevent AF, but its underlying electrophysiological mechanisms areobscure. The purpose of this study is to investigate the effects of irbesartan on atrial cellelectrophysiology.
