We consider the flow of an incompressible viscous Maxwell fluid between two parallel plates, initially induced by a constant pressure gradient. The pressure gradient is withdrawn and the upper plate moves with a unifo...We consider the flow of an incompressible viscous Maxwell fluid between two parallel plates, initially induced by a constant pressure gradient. The pressure gradient is withdrawn and the upper plate moves with a uniform velocity while the lower plate continues to be at rest. The arising flow is referred to as run-up flow. The unsteady governing equations are solved as initial value problem using Laplace transform technique. The expression for velocity, shear stresses on both plates and discharge are obtained. The behavior of the velocity, shear stresses and mass flux has been discussed in detail with respect to variations in different governing flow parameters and is presented through graphs.展开更多
A potential acceleration of a quantum open system is of fundamental interest in quantum computation, quantum communication, and quantum metrology. In this paper, we investigate the "quantum speed-up capacity" which ...A potential acceleration of a quantum open system is of fundamental interest in quantum computation, quantum communication, and quantum metrology. In this paper, we investigate the "quantum speed-up capacity" which reveals the potential ability of a quantum system to be accelerated. We explore the evolutions of the speed-up capacity in different quantum channels for two-qubit states. We find that although the dynamics of the capacity is varying in different kinds of channels, it is positive in most situations which are considered in the context except one case in the amplitude-damping channel. We give the reasons for the different features of the dynamics. Anyway, the speed-up capacity can be improved by the memory effect. We find two ways which may be used to control the capacity in an experiment: selecting an appropriate coefficient of an initial state or changing the memory degree of environments.展开更多
目的观察钾通道开放剂尼可地尔对冠心病Warm-up现象及患者反复运动后心率恢复(HRR)的影响。方法选择运动试验阳性以及经冠脉造影证实至少单支冠脉狭窄程度在70%~90%的慢性稳定型心绞痛患者75例。根据干预药物不同分为对照组(常规治...目的观察钾通道开放剂尼可地尔对冠心病Warm-up现象及患者反复运动后心率恢复(HRR)的影响。方法选择运动试验阳性以及经冠脉造影证实至少单支冠脉狭窄程度在70%~90%的慢性稳定型心绞痛患者75例。根据干预药物不同分为对照组(常规治疗)、尼可地尔组(常规治疗+尼可地尔口服5 mg,3次/d)及单硝酸异山梨酯组(常规治疗+单硝酸异山梨酯口服20 mg,2次/d),各25例。各组均服药6个月以上。通过间隔15 min的连续两次运动试验(EX1与EX2)来观察各组缺血阈值(ST段压低0.1 m V时心率血压乘积即RPP值)、出现ST段压低0.1 m V时间(T-STD)、ST段压低的最大值(STDmax)、ST段恢复压低0.05 m V时间、总运动时间(ED)等反映心电图缺血情况的指标以及HRR的变化。结果 3组前后两次运动相比,EX2各指标均较EX1有明显改善(P均〈0.05);单硝酸异山梨酯组仅STDmax高于对照组(P〈0.05);尼可地尔组在RPP、T-STD、ST段恢复压低0.05m V时间、STDmax方面均明显优于对照组(P均〈0.01)和单硝酸异山梨酯组(P〈0.05或〈0.01);尼可地尔组EX1后与EX2后HRR比较,P〈0.01,与对照组比较,P〈0.05。结论尼可地尔可促进冠心病Warm-up现象的发生,钾通道可能作为重要机制参与其中;同时尼可地尔有利于HRR。展开更多
文摘We consider the flow of an incompressible viscous Maxwell fluid between two parallel plates, initially induced by a constant pressure gradient. The pressure gradient is withdrawn and the upper plate moves with a uniform velocity while the lower plate continues to be at rest. The arising flow is referred to as run-up flow. The unsteady governing equations are solved as initial value problem using Laplace transform technique. The expression for velocity, shear stresses on both plates and discharge are obtained. The behavior of the velocity, shear stresses and mass flux has been discussed in detail with respect to variations in different governing flow parameters and is presented through graphs.
基金supported by the EU FP7 Marie–Curie Career Integration Fund(Grant No.631883)the Royal Society Research Fund(Grant No.RG150036)the Fundamental Research Fund for the Central Universities,China(Grant No.2018IB010)
文摘A potential acceleration of a quantum open system is of fundamental interest in quantum computation, quantum communication, and quantum metrology. In this paper, we investigate the "quantum speed-up capacity" which reveals the potential ability of a quantum system to be accelerated. We explore the evolutions of the speed-up capacity in different quantum channels for two-qubit states. We find that although the dynamics of the capacity is varying in different kinds of channels, it is positive in most situations which are considered in the context except one case in the amplitude-damping channel. We give the reasons for the different features of the dynamics. Anyway, the speed-up capacity can be improved by the memory effect. We find two ways which may be used to control the capacity in an experiment: selecting an appropriate coefficient of an initial state or changing the memory degree of environments.
文摘目的观察钾通道开放剂尼可地尔对冠心病Warm-up现象及患者反复运动后心率恢复(HRR)的影响。方法选择运动试验阳性以及经冠脉造影证实至少单支冠脉狭窄程度在70%~90%的慢性稳定型心绞痛患者75例。根据干预药物不同分为对照组(常规治疗)、尼可地尔组(常规治疗+尼可地尔口服5 mg,3次/d)及单硝酸异山梨酯组(常规治疗+单硝酸异山梨酯口服20 mg,2次/d),各25例。各组均服药6个月以上。通过间隔15 min的连续两次运动试验(EX1与EX2)来观察各组缺血阈值(ST段压低0.1 m V时心率血压乘积即RPP值)、出现ST段压低0.1 m V时间(T-STD)、ST段压低的最大值(STDmax)、ST段恢复压低0.05 m V时间、总运动时间(ED)等反映心电图缺血情况的指标以及HRR的变化。结果 3组前后两次运动相比,EX2各指标均较EX1有明显改善(P均〈0.05);单硝酸异山梨酯组仅STDmax高于对照组(P〈0.05);尼可地尔组在RPP、T-STD、ST段恢复压低0.05m V时间、STDmax方面均明显优于对照组(P均〈0.01)和单硝酸异山梨酯组(P〈0.05或〈0.01);尼可地尔组EX1后与EX2后HRR比较,P〈0.01,与对照组比较,P〈0.05。结论尼可地尔可促进冠心病Warm-up现象的发生,钾通道可能作为重要机制参与其中;同时尼可地尔有利于HRR。