Mechanical properties and kinetics of thermally aged Z3CN20.09M cast duplex stainless steel

Cast stainless steels used in nuclear power plants suffer from fracture toughness losses owing to thermal aging after long-term service at temperatures ranging from 280–320°C. To study the thermal aging embrittlement of Z3 CN20.09 M duplex stainless steel produced in China, accelerated thermal aging experiments were carried out at 350, 380, and 400°C for up to 10000 h. Microhardness and Charpy impact energies were measured at different aging times. The microhardness of ferrite increased drastically over the initial aging time of 2000 h at 380 and 400°C and then slowly reached HV0.01 560. In contrast to this observed change in microhardness, Charpy impact energies sharply decreased after initial aging and then gradually reached a minimum value. Taking the microhardness of the ferrite phase as the parameter describing the thermal kinetics of the stainless steel samples, the activation energy of thermal aging was calculated to be 51 kJ/mol. Correlations between the thermal aging parameter, P, and ferrite microhardness and between P and Charpy impact energy were also analyzed. The results showed that the activation energy calculated from the ferrite microhardness is much more reasonable than that obtained using other parameters, such as chemical composition and impact energy.

The neuroprotective role of Panax notoginseng saponins in APP/PS1 transgenic mice through the modulation of cerebrovascular

Background:Panax notoginseng saponins(PNS)is extracted from Sanqi(Panax notoginseng),which is a valuable herb and has been widely used in traditional Chinese medicine for the treatment of cerebrovascular diseases and pain.PNS has been proved to promote blood circulation and angiogenesis by inhibiting platelet aggregation.In our previous study,PNS accompanied with geniposide can prevent Alzheimer’s disease(AD).However,the efficacy of PNS and its potential mechanism in AD remain unclear.Methods:Amyloid precursor protein/presenilin-1(APP/PS1)transgenic(Tg)mice were used as AD-like animal models.Wild-type mice and APP/PS1 transgenic were administrated with saline solution while mice in PNS treatment group were administrated with PNS at a dosage of 17 mg/kg/day for three months.Morris water maze(MWM)was applied to evaluate the spatial learning and memory and step-down test was used to evaluate the cognitive function.1%Thioflavin-S staining was used to calculate the average number amyloid plaques in cortex and hippocampus.CD31 staining was detected to observe the density of cerebrovascular in hippocampus areas and CD105 staining was further detected to evaluate angiogenesis.Laser Doppler PeriFlux 5000 was further measured the change of cerebrovascular blood flow.ChemDraw was used to draw the molecular structures of five main ingredients of PNS.AlzPlatform were used to estimate the potential targets of PNS.Results:By a bench of behavioral tests,PNS showed a better tendency in proving cognitive functions.In addition,the amyloid plaques in both cortex and hippocampus were significantly reduced after PNS intervention(P<0.05 and P<0.001 respectively).Furthermore,the density of cerebrovascular in the hippocampus areas was increased under PNS administration(P<0.001),which accompanied with angiogenesis in dentate gyrus areas and cerebrovascular blood flow promotion(P<0.05).By AlzPlatform docking serve,we screened five major ingredients of PNS-R1,Rd,Rb1,Re and Rg1.These screening data suggested that vascular related proteins could be the one of potential targets of PNS,such as platelet activating factor receptor and vasopressin V1a receptor.Conclusion:By modulating cerebrovascular function,PNS can reduce the deposition of amyloid plaques and exhibit the role of neuroprotection in a preventive strategy.

Relativistic motion on Gaussian quantum steering for two-mode localized Gaussian states

Realistic quantum systems always exhibit gravitational and relativistic features.In this paper,we investigate the properties of Gaussian steering and its asymmetry by the localized two-mode Gaussian quantum states,instead of the traditional single-mode approximation method in the relativistic setting.We find that the one-side Gaussian quantum steering will monotonically decrease with increasing observers of acceleration.Meanwhile,our results also reveal the interesting behavior of the Gaussian steering asymmetry,which increases for a specific range of accelerated parameter and then gradually approaches to a finite value.Such finding is well consistent and explained by the well-known Unruh effect,which could significantly destroy the one-side Gaussian quantum steering.Finally,our results could also be applied to the dynamical studies of Gaussian steering between the Earth and satellites,since the effects of acceleration are equal to the effects of gravity according to the equivalence principle.

Quantum fluctuation of entanglement for accelerated two-level detectors

It is well known that the quantum fluctuation of entanglement(QFE) between Unruh–De Witt detector(modeled by a two-level atom) is always investigated in a relativistic setting. However, both of the Unruh radiation and quantum fluctuation effects play an important role in precise measurements of quantum entanglement. In this paper, we have quantitatively analyzed how the relativistic motion affects the QFE for two entangled Unruh–De Witt detectors, one of which is accelerated and interacting with the neighbor external scalar field. Our results show that the QFE, which initially increases by the Unruh thermal noise, will suddenly decay when the acceleration reaches to a considerably large value. Therefore, the relativistic effect will lead to non-negligible QFE effect. We also find that the initial QFE(without acceleration effect) reaches its minimum value at the maximally entangled state and the separable state. More importantly, our analysis demonstrates that although the QFE has a huge decay when the acceleration is greater than ~ 0.96, the ratio of △E/C is still very large, due to the simultaneous decay of concurrence to a very low value. Finally, enlightened by the well-known equivalence principle,we discuss the possibility of applying the above findings to the dynamics of QFE under the influence of gravitation field.

Theoretical Characteristics of Tibetan Medicine

Similar to traditional Chinese medicine(TCM),Tibetan medicine emphasizes the concepts of holism,balance,and etiology.With the individual as the nexus of macro-and micro-ecologies,multi-layered systemic etiologies,inform therapeutic pharmacologies for cultivating network effects to induce the healing response.Tibetan medicine approaches health and healing through perspectives that frame the balance achieved in the internal world as inextricably linked to balance in the external world,and vice versa,that includes expressions of mind and consciousness.The external world refers to the broader context of the natural world as comprised of matter and energy expressed through five elemental dynamics(Chi.Tu,Shui,Huo,Feng and Kong;Tib.Sa,Chu,Mé,r Lung and Kha)describing principles of solidity,cohesion,heat,motility,and interactive space,or earth,water,fire,wind and space,respectively.The internal world refers to the local context of the physical mass and biochemical cascades of energy transfers comprising the human body,its behaviors and functions,including cognitive factors,as also expressed through the five elemental dynamics.The external and internal systems merge as a unified whole,where the five elemental dynamics characterize materio-energetic exchanges between the broader and local ecologies of individual body and natural world,as well as social relations,mental affects,and contextual conditions.The interdependence,opposition,restriction and transformation among three physiological systems known as nyépa(Three Causal Factors)-r Lung,Tripa and Béken(pronounced lōōng,trīpa,baekan,respectively)-are used to discuss the balance of the whole.The causal origins of disease are explained through disturbances to these systems as a combination of afflictive mental factors,physiologic imbalances,and disturbing conditions from the natural world,such as environmental toxins,pathogens,and exposures.Of the three causal origins,afflictive mental factors are particularly emphasized as important etiological conditioning influences.Initiation and progression of disease is divided into four stages:baseline stage,initiating stage,developing stage,and maturing stage.Each stage has an explicit therapeutic paradigm for treatment,recovery,and health maintenance demonstrating the distinct theoretical framework for disease treatment in Tibetan medicine as specific to individual body,particular disease etiology,and constitutionally-directed unique compound metabolism pharmacodynamically.