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Wettability,reactivity,and interface structure in Mg/Ni system

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j.urnal of Magnesium and Alloys 2024年第2期12卷 659-672页

作者： S.Terlicka N.Sobczak Ł.Maj.P.Darłak j.j.Sobczak Institute of Metallurgy and Materials Science Polish Academy of Sciences25 Reymonta Str.KrakowPoland Faculty of Foundry Engineering AGH University23 Reymonta Str.KrakowPoland

The sessile drop method was applied to the experimental investigation of the wetting and spreading behaviors of liquid Mg drops on pure Ni *** comparison,the experiments were performed in two variants:(1)using the Capillary Purification(CP)procedure,which allows the non-contact heating and squeezing of a pure oxide-free Mg drop;(2)by classical Contact Heating(CH)*** high-temperature tests were performed under isothermal conditions(CP:760℃for 30 s;CH:715℃for 300 s)using Ar+5 wt%H_(2) *** the sessile drop tests,images of the Mg/Ni couples were recorded by CCD cameras(57 fps),which were then applied to calculate the contact angles of metal/substrate *** and transmission electron microscopy analyses,both coupled with energy-dispersive X-ray spectroscopy,were used for detailed structural characterization of the solidified *** was found that an oxide-free Mg drop obtained by the CP procedure showed a wetting phenomenon on the Ni substrate(an average contact angleθ<90°in<1 s),followed by fast spreading and good wetting over the Ni substrate(θ_((CP))~20°in 5 s)to form a final contact angle ofθ_(f(CP))~18°.In contrast,a different wetting behavior was observed for the CH procedure,where the unavoidable primary oxide film on the Mg surface blocked the spreading of liquid Mg showing apparently non-wetting behavior after 300 s contact at the test ***,in both cases,the deep craters formed in the Ni substrates under the Mg drops and significant change in the structure of initially pure Mg drops to Mg-Ni alloys suggest a strong dissolution of Ni in liquid Mg and apparent values of the final contact angles measured for the Mg/Ni system.

关键词： Magnesium-based alloys Sessile drop tests Capillary purification procedure Wettability Reactivity Contact angle

COVID-19感知易感性对健康风险感知、风险规避和出游意愿的影响:政府信任的调节作用(英文)

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j.urnal of Resources and Ecology 2024年第3期15卷 733-744页

作者：周彬王璐婷王灵恩 chris Ryan 刘思怡熊启昊王玉欣宁波大学旅游系浙江宁波315211 中国科学院地理科学与资源研究所北京100101 怀卡托大学中国-新西兰旅游研究中心新西兰哈密尔顿3240 科廷大学商学与法学院管理与营销系澳大利亚珀斯6102

本研究考察了COVID-19感知易感性、健康风险感知、风险规避与出游意愿之间的关系,并探讨了政府信任的调节作用。研究数据通过腾讯问卷(113)和实地调研(507)两种方法收集。研究发现:感知易感性显著影响健康风险感知和风险规避,这2个变量... 详细信息

本研究考察了COVID-19感知易感性、健康风险感知、风险规避与出游意愿之间的关系,并探讨了政府信任的调节作用。研究数据通过腾讯问卷(113)和实地调研(507)两种方法收集。研究发现:感知易感性显著影响健康风险感知和风险规避,这2个变量又显著影响游客的出游意愿。健康风险感知和风险规避分别在感知易感性影响出游意愿发挥部分中介作用,它们之间的链式中介关系也得到支持。政府信任在感知易感性影响健康风险感知,以及健康风险感知和出游意愿之间有显著的调节作用。本研究对全球公共卫生危机游客出游意愿的影响因素提供了新的见解,有助于后疫情时代旅游经济复苏和目的地的营销策略制定。

关键词：感知易感性健康风险感知风险规避出游意愿政府信任

Study of the Physical and Mechanical Properties of Titanium in Volume by the MEAM Method

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Modeling and Numerical Simulation of Material Science 2024年第1期14卷 58-68页

作者： Yahnn j. Mighensle Mimboui Alain S. Dzabana Honguelet Timothée Nsongo Faculty of Science and Technology Marien Ngouabi University Brazzaville Congo Research Group on Physical and Chemical Properties of Materials Brazzaville Congo Association Alpha Sciences Beta Technologies Brazzaville Congo Geological and Mining Research Centre Brazzaville Congo

In this work we present the results of our study on the physical and mechanical properties of titanium in volume. The work consisted in determining its physical and mechanical properties under different crystallographic structures (HCP, FCC, BCC and SC) using the Modified Embedded Atom Method (MEAM) and the MEAM potential of titanium. We used the LAMMPS calculation code, based on classical molecular dynamics, to determine the most stable structure of titanium, which is the hexagonal compact structure (HCP) with crystal parameters a = 2.952 Å and c = 4.821 Å and a cohesion energy of -4.87 eV. This structure is seconded by the cubic centred structure (BCC) with a lattice parameter a = 3.274 Å and a cohesive energy of -4.84 eV. It was shown that titanium can crystallise into a third structure which is the face-centred cubic (FCC) structure with a lattice parameter a = 4.143 Å and a cohesive energy of -4.82 eV. The results obtained in this study were compared with the theoretical results and showed considerable agreement.

关键词： MEAM Potential LAMMPS Code Molecular Dynamics Elastic Constants Modules Ovito

Utilization of Logistical Regression to the Modified Sine-Gordon Model in the MST Experiment

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Open j.urnal of Modelling and Simulation 2024年第2期12卷 43-58页

作者： Nizar j. Alkhateeb Hameed K. Ebraheem Eman M. Al-Otaibi Department of Electronic Engineering Technology College of Technological Studies (CTS) The Public Authority of Applied Education and Training (PAAET) Kuwait City Kuwait

In this paper, a logistical regression statistical analysis (LR) is presented for a set of variables used in experimental measurements in reversed field pinch (RFP) machines, commonly known as “slinky mode” (SM), observed to travel around the torus in Madison Symmetric Torus (MST). The LR analysis is used to utilize the modified Sine-Gordon dynamic equation model to predict with high confidence whether the slinky mode will lock or not lock when compared to the experimentally measured motion of the slinky mode. It is observed that under certain conditions, the slinky mode “locks” at or near the intersection of poloidal and/or toroidal gaps in MST. However, locked mode cease to travel around the torus;while unlocked mode keeps traveling without a change in the energy, making it hard to determine an exact set of conditions to predict locking/unlocking behaviour. The significant key model parameters determined by LR analysis are shown to improve the Sine-Gordon model’s ability to determine the locking/unlocking of magnetohydrodyamic (MHD) modes. The LR analysis of measured variables provides high confidence in anticipating locking versus unlocking of slinky mode proven by relational comparisons between simulations and the experimentally measured motion of the slinky mode in MST.

关键词： Madison Symmetric Torus (MST) Magnetohydrodyamic (MHD) Sine-Gordon Toroidal Dynamic Modelling Reversed Field Pinch (RFP) Logistical Regression

Bivariate Analysis of Pollutants Monthly Maxima in Mexico City Using Extreme Value Distributions and Copula

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j.urnal of Environmental Protection 2024年第7期15卷 796-826页

作者： j.an A. Vazquez-Morales Eliane R. Rodrigues Hortensia j. Reyes-Cervantes Facultad de Ciencias Fsico-Matemticas Benemrita Universidad Autnoma de Puebla Puebla Mexico Instituto de Matemticas Universidad Nacional Autnoma de Mxico Mexico City Mexico

In the present work, we are interested in studying the j.int distributions of pairs of the monthly maxima of the pollutants used by the environmental authorities in Mexico City to classify the air quality in the metropolitan area. In order to obtain the j.int distributions a copula will be considered. Since we are analyzing the monthly maxima, the extreme value distributions of Weibull and Fréchet are taken into account. Using these two distributions as marginal distributions in the copula a Bayesian inference was made in order to estimate the parameters of both distributions and also the association parameters appearing in the copula model. The pollutants taken into account are ozone, nitrogen dioxide, sulphur dioxide, carbon monoxide, and particulate matter with diameters smaller than 10 and 2.5 microns obtained from the Mexico City monitoring network. The estimation was performed by taking samples of the parameters generated through a Markov chain Monte Carlo algorithm implemented using the software OpenBugs. Once the algorithm is implemented it is applied to the pairs of pollutants where one of the coordinates of the pair is ozone and the other varies on the set of the remaining pollutants. Depending on the pollutant and the region where they were collected, different results were obtained. Hence, in some cases we have that the best model is that where we have a Fréchet distribution as the marginal distribution for the measurements of both pollutants and in others the most suitable model is the one assuming a Fréchet for ozone and a Weibull for the other pollutant. Results show that, in the present case, the estimated association parameter is a good representation to the correlation parameters between the pair of pollutants analyzed. Additionally, it is a straightforward task to obtain these correlation parameters from the corresponding association parameters.

关键词： Copula Extreme Value Distribution Bayesian Inference Air Pollution Mexico City

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观看盗版,不减反增盗版网站流量大增

空中英语教室（高级版．彭蒙惠英语） 2024年第7期 6-7,38页

作者： chris Stokel-Walker 不详

网络盗版存在的时间几乎和互联网一样久,随着影音流媒体服务的数量与价格激增,使用盗版平台的潜在诱惑也随之增加。英国反盗版分析机构MUSO与科尔尼顾问管理公司的一份新分析展现了盗版的规模到底有多庞大。2023年,在线盗版网站的访问... 详细信息

网络盗版存在的时间几乎和互联网一样久,随着影音流媒体服务的数量与价格激增,使用盗版平台的潜在诱惑也随之增加。英国反盗版分析机构MUSO与科尔尼顾问管理公司的一份新分析展现了盗版的规模到底有多庞大。2023年,在线盗版网站的访问量高达1410亿次,相当于日访问量约3.86亿次。MUSO指出,这一数字自2019年以来增长了12%。

关键词：流媒体服务网站流量互联网访问量网络盗版反盗版科尔尼

Theory and classification of mass extinction causation

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National Science Review 2024年第1期11卷 16-36页

作者： Thomas j.Algeo j.n Shen State Key Laboratory of Biogeology and Environmental Geology China University of Geosciences—Wuhan State Key Laboratory of Geological Processes and Mineral Resources China University of Geosciences—Wuhan Department of Geosciences University of Cincinnati

Theory regarding the causation of mass extinctions is in need of systematization, which is the focus of this contribution. Every mass extinction has both an ultimate cause, i.e. the trigger that leads to various climato-environmental changes, and one or more proximate cause(s), i.e. the specific climato-environmental changes that result in elevated biotic mortality. With regard to ultimate causes, strong cases can be made that bolide(i.e. meteor) impacts, large igneous province(LIP) eruptions and bioevolutionary events have each triggered one or more of the Phanerozoic Big Five mass extinctions, and that tectono-oceanic changes have triggered some second-order extinction events. Apart from bolide impacts, other astronomical triggers(*** flares, gamma bursts and supernova explosions) remain entirely in the realm of speculation. With regard to proximate mechanisms, most extinctions are related to either carbon-release or carbon-burial processes, the former being associated with climatic warming, ocean acidification, reduced marine productivity and lower carbonate δ13C values, and the latter with climatic cooling, increased marine productivity and higher carbonate δ13C values. Environmental parameters such as marine redox conditions and terrestrial weathering intensity do not show consistent relationships with carbon-cycle *** this context, mass extinction causation can be usefully classified using a matrix of ultimate and proximate factors. Among the Big Five mass extinctions, the end-Cretaceous biocrisis is an example of a bolide-triggered carbon-release event, the end-Permian and end-Triassic biocrises are examples of LIP-triggered carbon-release events, and the Late Ordovician and Late Devonian biocrises are examples of bioevolution-triggered carbon-burial events. Whereas the bolide-impact and LIP-eruption mechanisms appear to invariably cause carbon release, bioevolutionary triggers can result in variable carbon-cycle changes, e.g. carbon burial durin

关键词： biocrisis ultimate cause proximate cause bolide large igneous province bioevolutionary event

First-principles calculations to investigate structural,electronic,magnetic,optical and thermodynamic properties of RE_(2)Rh_(3)Ge(RE=Pr,Sm)

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j.urnal of Rare Earths 2024年第7期42卷 1385-1393,I0007页

作者： A.Ezaier R.Masrour M.Hamedoun j.Kharbach A.Rezzouk A.Hourmatallah N.Benzakour K.Bouslykhane Laboratory of Solid Physics Faculty of Sciences Dhar El MehrazSidi Mohamed Ben Abdellah UniversityBP 1796FezMorocco Equipe de Physique du Solide LaboratoiresLIPIEcole Normale SupérieureBensoudaFèsMorocco

In this paper,we analyzed the physical characteristics of the ternary alloys RE_(2)Rh_(3)Ge(RE=Pr and Sm)using the first principles calculation based on functional density theory integrated in the Wien2k *** calculated formation energies of Pr_(2)Rh_(3)Ge and Sm_(2)Rh_(3)Ge are−5.3827 and−5.2782 eV/atom,respectively,showing that these alloys may exist *** results of the band structure and density of states indicate that all of the compounds tested are magnetic metals,and their magnetism is mostly related to the contribution of Pr and Sm *** total magnetic moments of Pr_(2)Rh_(3)Ge and Sm_(2)Rh_(3)Ge are 4.07245 and 11.16161μB/f.u,*** parameters such as heat capacity at constant pressure,entropy,Debye temperature,lattice volume,compressibility coefficients,and Grüneisen parameter alloys were calculated using the Gibbs algorithm and studied in depth over a large temperature range of 0-900 *** Debye temperature increases with increasing pressure and decreases with decreasing ***,the Debye temperatures calculated at p=0 GPa and T=300 K are equal to be 342 and 322 K for Pr_(2)Rh_(3)Ge and Sm_(2)Rh_(3)Ge,*** optical characteristics such as the real and imaginary portions of the dielectric function,the absorption coefficient,the energy-loss function,and the refractive index were investigated and discussed in more depth.

关键词： Magnetic metals Functional density theory Density of states Magnetic moment Optical and thermodynamic properties Rare earths

In situ characterization of particle formation in spray flame synthesis using wide-angle light scattering

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Particuology 2024年第3期86卷 304-312页

作者： Simon Aβmann Franz j.T.Huber Stefan Will Lehrstuhl für Technische Thermodynamik(LTT) Friedrich-Alexander-Universitat Erlangen-Nürnberg(FAU)Erlangen91058Germany Erlangen Graduate Schoolin Advanced Optical Technologies(SAOT) Friedrich-Alexander-Universitat Erlangen-Nurnberg(FAU)Erlangen91052Germany Competence Unit Engineering of Advanced Materials(EAM) Friedrich-Alexander-Universitat Erlangen-Nürnberg(FAU)Erlangen91052Germany

Wide-angle light scattering(WALS)was used for in situ measurements of droplet and nanoparticle size distributions during the synthesis of titania and iron oxide particles from liquid precursor solutions in the standardized SpraySyn burner for spray flame *** was synthesized from titanium tetraisopropoxide(TTIP)and iron oxide from iron(II)nitrate nonahydrate(INN)using ethanol(EtOH)as *** images were taken at heights up to 120 mm above the burner surface and classified into droplet and particle *** size distributions were derived from a sequential analysis of scattering data containing the oscillating Mie pattern,the lognormal size distribution parameters for spherical and fractal particle fractions from a multivariate approach on averaged particle scattering *** results show that the precursor addition leads to altered evaporation behavior and even droplet disruption probably induced by puffing or micro-explosions compared to pure *** the case of TTIP(a hygroscopic alkoxide),the synthesis of a large fraction of spheres was observed,while the nitrate INN leads to the formation of mostly fractal aggregates.

关键词： Spray flame synthesis Metal oxide particles Elastic light scattering Droplet size distribution Nanoparticle morphology Particle size distribution