Influence Of Local Temperature Research Articles

Indistinguishability-assisted two-qubit entanglement distillation

Production of quantum states exhibiting a high degree of entanglement out of noisy conditions is one of the main goals of quantum information science. Here, we provide a conditional yet efficient entanglement distillation method which functions within the framework of spatially localized operations and classical communication. This method exploits indistinguishability effects due to the spatial overlap between two identical qubits in distinct sites and encompasses particle statistics imprint. We derive the general conditions for the maximum entanglement distillation out of mixed states. As applications, we give a thorough description of distilled entanglement and associated success probability starting from typical noisy states, such as thermal Gibbs states and Werner states. The influence of local temperatures and of a noise parameter is discussed, respectively, in these two cases. The proposed scheme paves the way towards quantum repeaters in composite networks made of controllable identical quantum particles.

Role of Surface-Active Element Sulfur on Thermal Behavior, Driving Forces, Fluid Flow and Solute Dilution in Laser Linear Welding of Dissimilar Metals

Understanding heat and mass transfer and fluid flow in the molten pool is very helpful in the selection and optimization of processing parameters, and the surface-active element has an important effect on the heat and mass transfer in laser welding of dissimilar metals. A three-dimensional (3D) numerical model coupled with a sub-model of surface tension, which considers the influence of local temperature and the concentration of surface-active element sulfur at the gas/liquid surface, is used to analyze the thermal behavior, driving forces, fluid flow, and solute dilution during laser linear welding of 304SS and Ni. The relationship between surface tension, driving forces, and the temperature coefficient of surface tension with the spatial distribution of temperature and the surface-active element sulfur is quantitatively analyzed. The simulation results show that the molten pool is fully developed at 45 ms, and the collision of inward and outward convection, with the maximum velocity reaching 1.7 m/s, occurs at the isotherm with a temperature between 2200 K and 2500 K. The temperature-gradient term and concentration-gradient term of surface shear stress play different roles in different positions of the free surface. The local sulfur concentration changes the temperature sensitivity of the surface tension at different sides of the free surface and further determines the transition of convection. Complex fluid flow promotes solute dilution, and the distribution of solute becomes uniform from the front to the rear of the molten pool. The Ni element is transferred to 304SS mainly at the rear side. The work provides theoretical support for the control of joint quality by changing the content of surface-active elements in dissimilar welding.

Spatiotemporal Variations of Extreme Precipitation in Wuling Mountain Area (China) and Their Connection to Potential Driving Factors

Changes in extreme precipitation have become a significant issue of regional disaster risk assessment and water resources management. Extreme precipitation variability is affected by multiple factors and shows disparities across different regions. Especially in mountain areas, geographic feature and local characteristics put more complexity and uncertainty on the changes of precipitation extremes. In this study, ten extreme precipitation indices of Wuling Mountain Area (WMA) during 1960–2019 have been used to analyzed the spatiotemporal variations of precipitation extremes. The relationships between extreme precipitation and potential driving factors, including geographic factors, global warming, local temperature, and climate indices, were investigated via correlation analysis. The results indicated that extreme precipitation tends to have a shorter duration and stronger intensity in WMA. Decreasing trends in R10mm, R20mm, R25mm, and the consecutive wet days (CWD) series account for 92%, 68%, 52%, and 96% of stations, while most stations in WMA have rising trends in Rx1day (68%), SDII (64%), R95p (72%), and R99p (72%). Significant abrupt changes in extreme precipitation indices mainly occurred in the 1980s–1990s. Geographic factors, local temperature, and climate indices exert different impacts on extreme precipitation. Longitude and elevation instead of latitude significantly affect extreme precipitation indices except for the maximum duration of wet spells. Global warming is likely to increase the intensity and decrease the duration of extreme precipitation, while the influence of local temperature is not exactly the same as that of global warming. The study reveals that summer monsoon indices are the dominant climate factor for variations of precipitation extremes in WMA. The correlation coefficient between extreme precipitation indices (such as Rx1day, R95p, R99p) and the East Asian summer monsoon index is around 0.5 and passed the significant test at the 0.01 level. The weakening of the summer monsoon indices tends to bring extreme precipitation with stronger intensity. The findings provide more understanding of the drivers and reasons of extreme precipitation changes in the mountain area.

The influence of local temperature and air velocity changes on the thermal sensations of users' working in surgical clothing

Thermal conditions in operating rooms are mainly dictated by the need to meet the safety/comfort requirements of the patient. However, the accuracy of performed surgical procedures depends on the surgeon and others members of medical team. Hence, their comfort sensation should be also factored in. The study sought to find out how thermal sensations of people working in surgical clothing can be modified through a local change in air velocity and temperature around the user. A series of tests was carried out with a thermal manikin to make an accurate assessment of the effectiveness of this type of equipment. The tests included changes of the ambient temperature, supply air temperature and air velocity. The operational efficiency was assessed on the basis of the equivalent temperature index ( teq). Results show that the final result of teq was mostly determined by air velocity rather than the supply air temperature.

Evidence for a three-phase sequence during Heinrich Stadial 4 using a multiproxy approach based on Greenland ice core records

Abstract. Glacial climate was characterised by two types of abrupt events. Greenland ice cores record Dansgaard–Oeschger events, marked by abrupt warming in-between cold, stadial phases. Six of these stadials appear related to major Heinrich events (HEs), identified from ice-rafted debris (IRD) and large excursions in carbon- and oxygen-stable isotopic ratios in North Atlantic deep sea sediments, documenting major ice sheet collapse events. This finding has led to the paradigm that glacial cold events are induced by the response of the Atlantic Meridional Overturning Circulation to such massive freshwater inputs, supported by sensitivity studies conducted with climate models of various complexities. These models also simulate synchronous Greenland temperature and lower-latitude hydrological changes. To investigate the sequence of events between climate changes at low latitudes and in Greenland, we provide here the first 17O-excess record from a Greenland ice core during Dansgaard–Oeschger events 7 to 13, encompassing H4 and H5. Combined with other ice core proxy records, our new 17O-excess data set demonstrates that stadials are generally characterised by low 17O-excess levels compared to interstadials. This can be interpreted as synchronous change of high-latitude temperature and lower-latitude hydrological cycle (relative humidity at the oceanic source of evaporation or change in the water mass trajectory/recharge) and/or an influence of local temperature on 17O-excess through kinetic effect at snow formation. As an exception from this general pattern, stadial 9 consists of three phases, characterised first by Greenland cooling during 550 ± 60 years (as shown by markers of Greenland temperature δ18O and δ15N), followed by a specific lower-latitude fingerprint as identified from several proxy records (abrupt decrease in 17O-excess, increase in CO2 and methane mixing ratio, heavier δD-CH4 and δ18Oatm), lasting 740 ± 60 years, itself ending approximately 390 ± 50 years prior to abrupt Greenland warming. We hypothesise that this lower-latitude signal may be the fingerprint of Heinrich event 4 in Greenland ice cores. The proposed decoupling between stable cold Greenland temperature and low-latitude climate variability identified for stadial 9 provides new targets for benchmarking climate model simulations and testing mechanisms associated with millennial variability.

Influence of local temperatures on the adhesion of the blank to abrasive grains

Kinetic data on the adhesion of the blank to an abrasive grain of the grinding wheel indicate that the bond between the abrasive and the metal is mainly due to capture [1]. According to current concepts regarding the bonding of materials in analogous conditions, the most important factors are the pressure, the temperature in the contact zone, and the time of exposure [2]. It is found that, in any grinding conditions, the contact surfaces of the abrasive grain with the chip and the blank include sections where the pressure exceeds the yield point of the material in the blank [3]. Experiments on metal adhesion to individual abrasive grains in microcutting (scratching) show that this process is intensified with increase in sample temperature [4]. To establish the relation between the adhesion rate and the local temperature in zones adjacent to the adhesive grain, the thermal interaction of the objects in contact during microcutting may be analyzed theoretically and investigated experimentally. In developing physical and mathematical models of the thermal process, the actual shape of the contacting objects—the blank, the abrasive grain, the chip, and the grain holder—is taken into account, as well as the location of individual sources of heat generation and their density distribution and also the temperature dependence of the thermophysical properties of the objects and the mechanical properties of the sample. In addition, the relative displacement of the contacting objects (the holder with the grain relative to the sample; and the chip relative to the grain) is taken into account. The components of the microcutting force required to calculate the power of the heat-generation sources are determined from analytical formulas [3]. It is assumed that the abrasive grain is a cone (vertex angle 2 γ ; wear length l 2 ). In other words, the grain is of the same shape as in experiments on microcutting (Fig. 1) [4]. Some of the heat from the abrasive grain passes to the holder.

Heat and hot air: influence of local temperature on journalists' coverage of global warming

This study examines relationships between local temperature in two cities (New York and Washington, D.C.) and coverage of global climate change in their local newspapers (the Times and the Post). The results show that there are some relationships between local temperature and frequency of attention to climate issues, such that journalists are more likely to discuss climate during unusually warm periods. However, support for the hypotheses was only partial; the Post did not show confirming relationships. The discussion focuses on implications for public understanding of climate change.

Influence of local temperature on electrical activity of supraoptic cells in vivo and in vitro

Influence of local temperature on electrical activity of supraoptic cells in vivo and in vitro

Thermally induced changes in neural and hormonal control of osmoregulation in a bird with salt glands (Anas platyrhynchos).

In conscious Pekin ducks adapted to hypertonic saline (1.9%) as drinking water, steady state secretion of the salt glands was established by continuous intravenous salt loading and the effects of hypothalamic thermal stimulation on salt gland activity and on the plasma concentrations of arginine vasotocin (AVT) and angiotensin II (AII) were observed. Hypothalamic cooling depressed salt gland secretion and the plasma level of AVT. Hypothalamic warming caused transient activation and subsequent inhibition of salt gland secretion without consistent changes of the plasma levels of AVT and AII. Whole body cooling by heat extraction with a colonic thermode produced moderate inhibition of salt gland activity, without changes in plasma AVT and AII, which may be explained by peripheral vasoconstriction. The results are consistent with the view that hypothalamic osmoregulation is under an influence of local temperature by combined osmo/thermo-responsiveness of hypothalamic neurons and temperature dependence of signal transmission in hypothalamic neural integration of osmoregulation.

Influence of local temperature and of digital nerve block on critical opening pressure of vessels in the finger.

Local cooling of the finger increased and local warming decreased the critical opening pressure of small vessels supplying the nailfold capillaries. Digital nerve block also decreased the critical closing pressure of these vessels independently of any concomitant change in local temperature.