the biqian-10 block, located in henan oilfield of sinopic, contains many thin and interbedded reservoirs, which have been operated by cyclic steam stimulation for 20 years or more. therefore, it is a challenge to implement the conventional steam flooding. in order to improve the recovery of steam flooding, urea was used to assist steam flooding. urea can decompose into co2 and nh3, which are be...

The present study investigated the mechanism underlying the transient potentiation of vasoconstriction by hypoxia in isolated porcine coronary arteries. Isometric tension was measured in rings with or without endothelium. Hypoxia (Po(2) <30 mmHg) caused a transient further increase in tension (hypoxic augmentation) in contracted (with U46619) preparations. The hypoxic response was endothelium d...

Large, elastic arteries buffer the pressure wave originating in the left ventricle and are constantly exposed to higher amplitudes of cyclic stretch (10%) than muscular arteries (2%). As a crucial factor for endothelial and smooth muscle cell function, cyclic stretch has, however, never been studied in ex vivo aortic segments of mice. To investigate the effects of cyclic stretch on vaso-reactiv...

This paper proposed a new type of unbonded areas which are preset in diffusion bonding titanium alloy laminates (DB-TAL). A group DB-TAL specimens with symmetric striped were prepared, and the fatigue experiments under tension–tension cyclic loading conducted. The crack growth behavior was studied from fracture surface. results show that this kind area can toughen based on mechanism. For toughe...

Epinephrine can enhance transmission under certain conditions in both the central and peripheral portions of the nervous system.'-6 Increased quantities of acetylcholine are released in response to epinephrine at ganglionic and neuromuscular junctions.4, s At the biochemical level, epinephrine stimulates the formation of adenosine 3',5'-phosphate (cyclic AMP) by preparations of many tissues, an...

frps (fiber reinforced polymer) possess many favorable characteristics suitable and applicable for construction industry when compared with steel reinforcement. there are new ideas to use frps as longitudinal or transverse reinforcement for new concrete elements particularly for bridge decks or beams. although high tensile strength of frp is main characteristic for applications at both areas, i...

We determined the effect of a-adrenergic receptor stimulation on cyclic adenosine monophosphate (cyclic AMP) concentrations in isolated myocytes derived from adult rat hearts and in isolated perfused rat hearts. Activation of a-adrenergic receptors with either phenylephrine (10~ M to 10~ M) or epinephrine (10" M to 10~ M) plus propranolol (10 ' M) resulted in a reduction in cyclic AMP levels in...

We determined the effect of alpha-adrenergic receptor stimulation on cyclic adenosine monophosphate (cyclic AMP) concentrations in isolated myocytes derived from adult rat hearts and in isolated perfused rat hearts. Activation of alpha-adrenergic receptors with either phenylephrine (10(-8) M to 10(-6) M) or epinephrine (10(-8) M to 10(-6) M) plus propranolol (10(-6) M) resulted in a reduction i...