Effect of the Variable B-Field on the Dynamic of a Central Electron Spin Coupled to an Anti-Ferromagnetic Qubit Bath

This present issue is an extension of the work of Y. Xiao-Zhong et al. who investigated the influence of constant external magnetic field on the decoherence of a central electron spin of atom coupled to an anti-ferromagnetic environment. We have shown in this work that the character variability of the field induces oscillations amongst the eigen modes of the environment. This observation is made via the derivation of the transition probability density of state, a manner by which critical parameters (parameters where transition occur) of the system could be obtained as it shows resonance peak. We equally observed that the two different magnons modes resulting from the frequency splitting via the application of the time-varying external B-Field, exhibit each a resonant peak of similar amplitude at different temperature ranges. This additional information shows that the probability for the central spin system to remain in its initially prepared diabatic state is enhanced for some temperature ranges for the corresponding two magnon modes. Hence, these temperature ranges where the probability density is maximum could save as decoherence free environment;an important requirement for the implementation of quantum computation and information processing in solid state circuitry. The theoretical and numerical results presented for the decoherence time and the probability density are that of a decohered central electron spin coupled to an anti-ferromagnetic spin bath. The theory is based on a spin wave approximation and on the density matrix using both transformations of Bloch, Primakov and Bogoliobuv in the adiabatic limit.

Evaluating and quantifying the effect of various spruce budworm intervention strategies on forest carbon dynamics in Atlantic Canada

Spruce budworm (SBW) outbreaks are one of the most devastating natural disturbances in spruce-balsam fir forests of eastern North America. Both early intervention strategy (EIS) and foliage protection strategy (FP) are being tested to limit forest losses, but the quantitative impact on forest carbon (C) dynamics is still unclear. In this study, we designed 19 separate scenarios of no intervention or varying success of EIS, FP, and their combination on SBW caused defoliation and mortality. We then used the TRIPLEX-Insect model to quantify their effects on forest C dynamics in the forests of the four provinces of Atlantic Canada. A scenario applying FP to 10%of the area with the greatest potential C losses of living biomass, protecting foliage in 10%of the forests is more realistic than higher proportion of FP given the high cost and large areas involved, resulted in reducing average cumulative net ecosystem productivity (NEP) from 2020 to 2039 by 56%–127%compared to a no outbreak scenario.Our results showed that FP would have to be applied everywhere to reduce tree mortality and increase NEP more than 8 years of successful EIS applied. However, if EIS can be successfully implemented for 12 years, it will maintain more forest C than FP applied everywhere during a moderate outbreak. We also found that the combination of EIS followed by FP in 10%of the areas disturbed by the SBW could maintain average cumulative NEP at similar levels to no defoliation in every province of Atlantic Canada. Black/red spruce forests younger than 60years old underwent the smallest changes in C dynamics whether using EIS, FP, or both. This highlights the importance of forest species, forest age, and their interactions on the effectiveness of a treatment during SBW outbreak. Overall, 31%–76%of the study area in Atlantic Canada could convert from a C sink to a source by 2039,if no protective measures are used under the worst-case scenarios, thus contributing to future climate warming.

Experimental and Numerical Investigation on High-Pressure Centrifugal Pumps:Ultimate Pressure Formulation,Fatigue Life Assessment and Topological Optimization of Discharge Section

A high percentage of failure in pump elements originates from fatigue.This study focuses on the discharge section behavior,made of ductile iron,under dynamic load.An experimental protocol is established to collect the strain under pressurization and depressurization tests at specific locations.These experimental results are used to formulate the ultimate pressure expression function of the strain and the lateral surface of the discharge section and to validate finite element modeling.Fe-Safe is then used to assess the fatigue life cycle using different types of fatigue criteria(Coffin-Manson,Morrow,Goodman,and Soderberg).When the pressure is under 3000 PSI,pumps have an unlimited service life of 107 cycles,regardless of the criterion.However,for a pressure of 3555 PSI,only the Morrow criterion denotes a significant decrease in fatigue life cycles,as it considers the average stress.The topological optimization is then applied to the most critical pump model(with the lowest fatigue life cycle)to increase its fatigue life.Using the solid isotropic material with a penalization approach,the Abaqus Topology OptimizationModule is employed.The goal is to reduce the strain energy density while keeping the volume within bounds.According to the findings,a 5%volume reduction causes the strain energy density to decrease from 1.06 to 0.66106 J/m^(3).According to Morrow,the fatigue life cycle at 3,555 PSI is 782,425 longer than the initial 309,742 cycles.

How can we increase attraction and retention of nurses? A research with young nurses

The persistent challenges in attracting and retaining a diverse healthcare workforce, with a specific focus on nurses, have become increasingly pronounced in recent years. These hurdles have been exacerbated by a growing difficulty in retaining young nurses, thereby exacerbating labor shortages driven by demographic shifts and the retirement of experienced nursing professionals. While most research efforts have concentrated on the broader issue of nurse retention, our study is centered on a specific demographic—young nurses. Our research endeavors to shed light on the unique challenges faced by young nurses through a qualitative survey involving nursing students who are simultaneously employed. We seek to discern the multifaceted obstacles they encounter in both their academic environment and the healthcare organizations where they work. While certain challenges are linked to course organization, examinations, and the time required for studying, our respondents overwhelmingly emphasize the pivotal role of the work environment in facilitating the harmonization of work, family, and educational commitments. This reconciliation is achieved through measures such as flexible working arrangements and the efficient organization of nursing duties. The primary objective of our research is to provide insights into how these diverse challenges can be effectively addressed and how a range of measures can significantly contribute to the attraction and retention of nursing students, as well as the long-term retention of nurses within the healthcare system. Our recommendations are intended to be of practical use to a wide array of stakeholders, including academic institutions, particularly colleges and universities offering nursing programs, as well as hospitals, clinics, and other healthcare institutions that hire nurses. By collaboratively addressing these challenges and implementing the recommended measures, we aim to fortify the healthcare workforce and ensure the continued provision of quality care to patients. .

Fabrication of Superhydrophobic Surfaces on Aluminum Alloy Via Electrodeposition of Copper Followed by Electrochemical Modification

Superhydrophobic aluminum surfaces have been prepared by means of electrodeposition of copper on aluminum surfaces, followed by electrochemical modification using stearic acid organic molecules. Scanning electron microscopy(SEM) images show that the electrodeposited copper films follow "island growth mode" in the form of microdots and their number densities increase with the rise of the negative deposition potentials. At an electrodeposition potential of-0.2 V the number density of the copper microdots are found to be 4.5×104cm^(-2)that are increased to 2.9×105cm^(-2)at a potential of-0.8 V. Systematically, the distances between the microdots are found to be reduced from 26.6 μm to 11.03 μm with the increase of negative electrochemical potential from-0.2 V to-0.8 V. X-ray diffraction(XRD) analyses have confirmed the formation of copper stearate on the stearic acid modified copper films. The roughness of the stearic acid modified electrodeposited copper films is found to increase with the increase in the density of the copper microdots. A critical copper deposition potential of-0.6 V in conjunction with the stearic acid modification provides a surface roughness of 6.2 μm with a water contact angle of 157?, resulting in superhydrophobic properties on the aluminum substrates.

INITIAL COEFFICIENT ESTIMATES FOR SOME SUBCLASSES OF M-FOLD SYMMETRIC BI-UNIVALENT FUNCTIONS

In the present investigation, we consider two new general subclasses B∑m（T, λ; α）and B^∑m （τ λ;β） of Em consisting of analytic and m-fold symmetric bi-univalent functions in the open unit disk U. For functions belonging to the two classes introduced here, we derive non-sharp estimates on the initial coefficients [a-~＋ll and │a2＋1│. Several connections to some of the earlier known results are also pointed out.

Seismic fragility assessment of low-rise stone masonry buildings

Many historic buildings in old urban centers in Eastern Canada are made of stone masonry reputed to be highly vulnerable to seismic loads.Seismic risk assessment of stone masonry buildings is therefore the first step in the risk mitigation process to provide adequate planning for retrofit and preservation of historical urban centers.This paper focuses on development of analytical displacement-based fragility curves reflecting the characteristics of existing stone masonry buildings in Eastern Canada.The old historic center of Quebec City has been selected as a typical study area.The standard fragility analysis combines the inelastic spectral displacement,a structure-dependent earthquake intensity measure,and the building damage state correlated to the induced building displacement.The proposed procedure consists of a three-step development process：（1） mechanics-based capacity model,（2） displacement-based damage model and（3） seismic demand model.The damage estimation for a uniform hazard scenario of 2% in 50 years probability of exceedance indicates that slight to moderate damage is the most probable damage experienced by these stone masonry buildings.Comparison is also made with fragility curves implicit in the seismic risk assessment tools Hazus and ELER.Hazus shows the highest probability of the occurrence of no to slight damage,whereas the highest probability of extensive and complete damage is predicted with ELER.This comparison shows the importance of the development of fragility curves specific to the generic construction characteristics in the study area and emphasizes the need for critical use of regional risk assessment tools and generated results.

Synergistic Effect of Halloyosite Nanotube and Nanocellulose on Thermal and Mechanical Properties of Poly(Ethylmethacrylate-co-Acrylonitrile)Bionanocomposites

This work reports a comprehensive study on poly(Ethylmethacrylateco-Acrylonitrile)Poly(EMA-AN)nanocomposites reinforced with a hybrid mixture of nanoreiforcements based on nanocrystals of cellulose(NCC)(1 or 5%wt)and halloysite nanotubes(HNTs)(1 or 5%wt).The morphology,thermal and mechanical properties of these nanocomposites were characterized.Homogeneous dispersion of the nanofillers has been shown by scanning electron microscopy.A significant increase of the rubbery modulus and glass transition temperature were obtained upon filler addition,due to the reduction of mobility of the matrix macromolecular chains.On the other hand,compared with the neat Poly(EMAAN),the storage modulus of the nanocomposites increased by a factor 38 when adding 5 wt%NCC and by 17 for the same concentration of HNTs.mechanical properties of ternary nanocomposites were furthers increased resulting from a synergistic effect of these two nanofillers.

Enslavement of Wireless Sensor Network to an RF Energy Harvesting System

The abundance of telecommunications systems makes it possible to have somewhat significant quantity of radiofrequency energy in the environment. This energy can be recycled to power ultra-low-power devices such as Wireless Sensor Network (WSN). In this paper, the performance of a miniature RF/DC converter is evaluated in order to enslave a WSN’s per-formance to the amount of the recovered energy. More precisely, a highly sensitive and efficient rectifier is designed to achieve optimum performance in the GSM band. The design method relies on a judicious choice of the rectifying diode which is the basis of most losses in a rectifying antenna (rectenna). Optimum performance is achieved by using the gradient method search proposed in the Advanced Design System (ADS) software. A rectifier based on Schottky diodes HSMS 2850 used in a voltage doubler topology is thus obtained. A maximum RF/DC conversion efficiency of 36% is reached for an RF input power level of 10 dBm. An energy budget of a sensor node in a WSN having an equitable distribution of network loads is then defined and used to evaluate the performance of the WSN regarding the distance at which the Base Station (BS) can be located. The Low Energy Adaptive Clustering Hierarchy (LEACH) protocol is used for this purpose. The distance separating the WSN from the BS is used as the enslavement parameter. Our analysis shows that increasing the duration of each round results in an increase in the range of the WSN. As an example, a network with 100 nodes distributed over an area of may be located at 1.3 km from the base station when each node of the WSN must perform measurements every 1 min.

镍铝化物增强摩擦堆焊Al-Cu-Mg合金基复合涂层的非等温时效行为

本文研究了镍铝化物对Al-Cu-Mg合金非等温时效行为的影响。对经非等温时效处理的含镍铝化物Al-Cu-Mg合金的组织、力学性能和耐蚀性进行了评价。结果表明,在Al-Cu-Mg基体中加入1.5 wt%Ni后,Al-Cu-Mg基体中镍铝化物的存在使析出物由S-Al_(2)CuMg转变为θ-Al_(2)Cu。在非等温时效过程中,达到最大力学性能的非等温时效处理温度由250℃转变为300℃。与170℃等温人工时效处理相比,经非等温时效处理的含镍铝化物Al-Cu-Mg合金的最大硬度和力学性能均提高了9%。含镍铝化物试样在300℃时达到最大硬度和抗剪强度,分别为HV0.1(143.4±6.4)和(298.6±9.6)MPa。非等温时效处理后,与AA2024铝合金基体和不含镍铝化物涂层相比,含镍涂层的腐蚀电流强度分别降低了约58%和49%。与传统的人工时效处理相比,经非等温时效处理的含镍铝涂层的腐蚀电流降低了16.7%。

Impact of Varying Blower Opening Degrees on Indoor Environment and Thermal Comfort

At present,air handling units are usually used indoors to improve the indoor environment quality.However,while introducing fresh air to improve air quality,air velocity has a certain impact on the occupants’thermal comfort.Therefore,it is necessary to explore the optimization of air-fluid-body interaction dynamics.In this study,the indoor air flow was changed by changing the opening and closing degree of the blower,and the thermal manikin is introduced to objectively evaluate the human thermal comfort under different air velocities.The main experimental results show that the air change rate increases with the increase of the opening and closing degree of the blower considering an ACH(air changes per hour)range between 3.8 and 10.For a better prediction,a linear correlation with a coefficient of 0.995 is proposed.As the blower’s opening is adjusted to 20%,25%,30%,35%,and 40%,the air velocity sensor positioned directly beneath the air inlet records average velocities of 0.19,0.20,0.21,0.28,and 0.34 m/s over four hours,respectively.Observations on thermal comfort and the average sensation experienced by individuals indicate an initial increase followed by a decline when the blower’s operation begins,with optimal conditions achieved at a 35%opening.These findings offer valuable insights for future indoor air ventilation and heat transfer design strategies.

Shear band formation in shaped rheocast aluminium component at various plunger velocities

Significant progress has been made in recent years in understanding and modelling the rheology of semi-solid metals.These models show the effects of the microstructure in terms of size and morphology of globules on the material response.More recently it has been shown that semi-solid metals can behave as compacted granular materials such as sand.A particular signature of such deformation is that the deformation becomes concentrated into shear bands which are 10-20 grains wide.Such bands have also been observed in a range of cast products.Recently, it has been clearly shown that shear bands in high pressure die cast (HPDC) products are also the results of Reynolds dilatancy.Shear bands are also known to be a common feature in semi-solid metal products.The segregation banding in semi-solid metal (SSM) material and its dependence of plunger velocity were investigated.Shaped castings were made with the RHEOMETALTM process with a range of different plunger velocities.The microstructural characteristics were investigated, with a particular emphasis on shear bands.It is shown that ingate velocities influence the location and characteristics of the shear bands.

Autonomous Wireless Sensors Network Based on Piezoelectric Energy Harvesting

Wireless sensor networks (WSNs) offer an attractive solution to many environmental, security and process monitoring. However, their lifetime remains very limited by battery capacity. Through the use of piezoelectric energy harvesting techniques, ambient vibration can be captured and converted into usable electricity to create selfpowering WSN which is not limited by finite battery energy. This paper investigates analytically and experimentally the performance of a WSN powered by a Piezoelectric Energy Harvesting System (PEHS) and a material block-level modeling considering most key energy consumption of a wireless sensor node in a star topology network is proposed. By using real hardware parameters of existing components, the proposed model is used to evaluate the energetic budget of the node. The sensor node performance is evaluated regarding transmit packet size, duty cycle and the number of nodes that can be deployed. From the spectral properties of the available vibration inside two moving vehicles (automobile and train), the maximal recoverable power for each type of vehicle is estimated. Using a PEHS based on a cantilever beam optimized for low-frequency applications, 6 mW power is recovered in the case of the train while a 12.5 mW power is reached in the case of the automobile. It is observed that the sink may not operate with the recovered energy. However, the sensor node can sense and transmit data with a maximum size of 105.5 kbits when the duty cycle is 4 × 10-15. It is also achieved that the node is most effective when the measured physical phenomena vary slowly, such as the variations in temperature due to thermal inertia. Considering an optimized PEHS based on non-linear processing, it is shown that the sink can operate for 190% improvement of the recovered power.

镁对Al-Mn-Mg-Si(3xxx)合金弥散相强化作用的影响（英文）

研究3xxx系合金中Mg对弥散相析出行为和力学性能的影响。通过光学显微镜和透射电子显微镜对铸造组织和热处理后的材料组织进行系统分析。结果显示:在弥散相析出过程中,合金中镁含量对弥散相的分布和体积分数有很大影响。室温下显微硬度和屈服强度随着镁含量的增加而增加。对热处理后的材料固溶强化机制和弥散强化机制进行量化分析。在经过热处理后的合金中,弥散相强化为主要的强化机制。提出了一个数学模型对材料在室温下的屈服强度进行预测。

Improvement of elevated-temperature strength and recrystallization resistance via Mn-containing dispersoid strengthening in Al-Mg-Si 6082 alloys

The precipitation behavior of Mn-containing dispersoids in Al-Mg-Si 6082 alloys with different Mn contents(0,0.5 and 1.0 wt%)during various heat treatments(300–500℃)was investigated.The effects of dispersoids on elevated-temperature strength and recrystallization resistance during hot-rolling and post-rolling annealing were evaluated.The results showed that the dispersoids in the Mn-containing alloys(0.5 and 1.0%)began to precipitate at 350℃and reached the optimum conditions after 2–4 h at 400℃.However,the dispersoids coarsened with increasing holding time at temperatures above450℃.After the peak precipitation treatment at 400℃for 2 h,the yield strength at 300℃increased from 28 MPa(base alloy free of Mn)to 55 MPa(alloy with 0.5%Mn)and 70 MPa(alloy with 1%Mn),respectively,demonstrating a significant dispersoid strengthening effect at elevated temperature.In addition,the dispersoids were thermally stable at 300℃for up to 1000 h holding owing to its relative high precipitation temperature(350–400℃),leading to the superior constant mechanical performance at elevated temperature during the long service life.During hot rolling and post-rolling annealing,the presence of a large amount of dispersoids results in the higher Zener drag PZcompared with base alloy and then significantly improved the recrystallization resistance.The alloy containing 0.5%Mn exhibited the highest recrystallization resistance among three experimental alloys studied during the post-rolling process,likely resulted from the lower coarsening rate of dispersoids and the lower dispersoids free zone.

热电集成助力光电化学分解水

光电催化水分解电池的核心吸光部件是半导体光电极.为实现太阳光下自发水分解,对于单光电极系统要求半导体光电极的带隙要不小于1.8 eV,以满足水分解反应的热力学(理论电压1.23 V)和动力学要求(热损耗与过电势~0.6 eV),而即便对于通过引入梯度带隙的双光电极构建串联型系统,背面的窄带隙光电极材料的带隙也通常需要大于1.0 eV.因此,传统的光电催化水分解电池难以有效利用太阳光谱中波长大于1250 nm的红外光,一定程度上限制了能量转化效率的提升.为实现太阳光谱的全谱有效利用,本文设计了一种热电器件集成的光电催化水分解系统,利用被太阳光谱中红外光加热的电解液作为热端、环境温度的水作为冷端,通过集成热电器件将二者温差转化为电压施加于光电催化水分解电池上以辅助分解水.对比传统串联型光电催化水分解电池,该热电器件集成的串联型光电催化电池的太阳能转化效率可提高近60%.本研究工作为构建可全光谱有效利用的光电催化水分解系统提供了具有普适性的策略.

One stop shop Ⅱ:taxonomic update with molecular phylogeny for important phytopathogenic genera:26–50(2019)

This paper is the second in a series focused on providing a stable platform for the taxonomy of phytopathogenic fungi.It focuses on 25 phytopathogenic genera:Alternaria,Bipolaris,Boeremia,Botryosphaeria,Calonectria,Coniella,Corticiaceae,Curvularia,Elsinoe,Entyloma,Erythricium,Fomitiporia,Fulviformes,Laetisaria,Limonomyces,Neofabraea,Neofusicoccum,Phaeoacremonium,Phellinotus,Phyllosticta,Plenodomus,Pseudopyricularia,Tilletia,Venturia and Waitea,using recent molecular data,up to date names and the latest taxonomic insights.For each genus a taxonomic background,diversity aspects,species identification and classification based on molecular phylogeny and recommended genetic markers are provided.In this study,varieties of the genus Boeremia have been elevated to species level.Botryosphaeria,Bipolaris,Curvularia,Neofusicoccum and Phyllosticta that were included in the One Stop Shop 1 paper are provided with updated entries,as many new species have been introduced to these genera.