Theoretical study of spin-forbidden cooling transitions of indium hydride using ab initio methods

The feasibility of spin-forbidden cooling of the In H molecule is investigated based on ab initio quantum chemistry calculations. The potential energy curves for the X^1Σ0^＋^＋, a^3Π0-, a^3Π0^＋, a^3Π1, a-3Π2, A-1Π1, 1-3Σ^0^-＋, and 1-3Σ1-＋states of In H are obtained based on multi-reference configuration interaction plus the Davidson corrections method. The calculated spectroscopic constants are in good agreement with the available experimental data. In addition, the influences of the active space and spin–orbit coupling effects on the potential energy curves and spectroscopic constants are also studied. For Re of a^3Π0^-, a^3Π0^＋, a^3Π1, and a-3Π2 states, the error from large active space is small. The potential energy curve of the A-1Π1state is not smooth for small active space. The spin–orbit coupling effects have great influences on the potential well depth and equilibrium internuclear distance of the A-1Π state. The Franck–Condon factors and radiative lifetimes are obtained on the basis of the transition dipole moments of the a^3Π0^＋）→ X^1Σ0^＋^＋, a-3Π1 → X-1Σ0^＋-＋, and A-1Π1 → X-1Σ0^＋^＋ transitions. Our calculation indicates that the a^3Π1（ ν＇= 0） → X-1Σ0^＋^＋（ν = 0） transition provides a highly diagonally distributed Franck–Condon factor and a short radiative lifetime for the a3Π1 state, which can ensure rapid and efficient laser cooling of In H.The proposed laser drives a-3Π1 → X-1Σ0^＋^＋ transitions by using three wavelengths.

Observation of Magnetic Dipole Forbidden Transitions in LHD and Its Application to Burning Plasma Diagnostics

Magnetic dipole forbidden （M1） transition was studied in large helical device （LHD） and F-, Si- and Ti-like M1 transitions are successfully observed for highly ionized Ar, Kr, Mo and Xe ions. The wavelengths measured in visible range for the heavy elements, which are carefully determined with extremely small uncertainties of 0.02 - 0.05 A as a standard wavelength of usual electric dipole （El） plasma emissions, are compared with theoretical predictions. The result shows a good agreement with recent Hatree-Fock calculation including semi-empirical adjustment. The M1 intensity for the F-like ions is examined by analyzing the intensity ratio of M1 to El. Density dependence of the ratio is experimentally verified by comparing with collisional- radiative model calculation on level population. The M1/E1 line ratio for the F-like ions is applied to the α （He^2＋） particle diagnostics in ITER, in which a steady-state operation of burning plasmas based on D-T fusion reaction is expected with α particle heating. Unfortunately, the present estimation suggests a negative result for the α particle measurement because the ratio is largely enhanced by the collisional excitation with bulk ions due to high ion temperature of ITER of 10 keV as assumed and the resultant effect of the collisional excitation with α particles becomes less. Meanwhile, the M1 transition, in particular, Ti-like WLIII （W^52＋） transition （3627 A） emitted in visible range, is very useful for diagnostics of the impurity behavior and the core plasma parameters in ITER.

Farm buildings and agri-food transitions in Southern France:Mapping dynamics using a stakeholder-based diagnosis

This study's goal is to present a dynamic portrait of the farm-buildings environment in Occitania,in Southern France,in order to better identify the transitions underway in agri-food chains.To this end,we undertook a ter-ritorial diagnosis based on actor statements,using 28 semi-structured interviews across Occitania.This diagnosis was enriched by graphic modelling,which enabled the spatialization of the dynamics described.We show that the process of standardisation of farm buildings prevails in the majority of the territories studied.This phenomenon has intensified in recent years with the development of vast photovoltaic-roofed sheds,accentuating the farm-land conversion and soil sealing.At the same time,in areas with strong environmental,landscape and heritage contexts,a'new adventure in farm buildings'(2022 survey)is taking shape.It is primarily driven by local short food chains,which rely on self-construction,repurposing and refurbishment,the sharing of tools and equipment,and which favour the use and reuse of local resources.This study shows that farm-buildings dynamics crystallise many challenges confronting the reterritorialisation of agriculture and food production.

Relativistic calculations on the transition electric dipole moments and radiative lifetimes of the spin-forbidden transitions in the antimony hydride molecule

Calculations on the spectroscopic constants and transition properties of the first three states(a^(1)△,b^(1)Σ^(+),and X3Σ-)of the Sb H molecule were performed under the relativistic framework using the exact two-component Hamiltonian(X2C).The potential energy curves in the Franck-Condon region were computed and compared with the previous values.Furthermore,the transition dipole moments for the weak spin-forbidden transitions(b0^(+)-X10^(+),b0^(+)-X_(2)1,X10^(+)-X_(2)1,and X_(2)1-a2)were reported.The spontaneous radiative lifetime of the b1Σ^(+)(υ′=0)state was calculated as 163.5±7.5μs,which is in reasonable agreement with the latest experimental value of 173±3μs.The spontaneous radiative lifetimes of the X_(2)1(υ′=0)state and the a2(υ′=0)state were calculated to be 48.6 s and~8 ms,respectively.Our study is expected to be a benchmark transition property computation for comparison with other theoretical and experimental results.The datasets presented in this paper,including the transition dipole moments,are openly available at https://dx.doi.org/10.11922/sciencedb.j00113.00018.

Assessment of challenges and strategies for driving energy transitions in emerging markets:A socio-technological systems perspective

The pursuit of improved quality of life standards has significantly influenced the contemporary mining model in the 21st century.This era is witnessing an unprecedented transformation driven by pressing concerns related to sustainability,climate change,the just energy transition,dynamic operating environments,and complex social challenges.Such transitions present both opportunities and obstacles.The aim of this study is to provide an extensive literature review on energy transition to identify the challenges and strategies associated with navigating transformations in energy systems.Understanding these transformations is particularly critical in the face of the severe consequences of global warming,where an accelerated energy transition is viewed as a universal remedy.Adopting a socio-technological systems perspective,specifically through the application of Actor Network Theory(ANT),this research provides a theoretical foundation while categorising challenges into five distinct domains and outlining strategies across these different dimensions.These insights are specifically tailored for emerging market countries to effectively navigate energy transition while fostering the development of resilient societies.Furthermore,our findings highlight that energy transition encompasses more than a mere technological shift;it entails fundamental changes in various systemic socio-economic imperatives.Through focusing on the role of social structures in transitions,this study makes a significant and innovative contribution to ANT,which has historically been criticised for its limited acknowledgement of social structures.Consequently,we propose an emerging market energy transition framework,which not only addresses technological aspects,but also integrates social considerations.This framework paves the way for future research and exploration of energy transition dynamics.The outcomes of this study offer valuable insights to policymakers,researchers,and practitioners engaged in the mining industry,enabling them to comprehend the multifaceted challenges involved and providing practical strategies for effective resolution.Through incorporating the social dimension into the analysis,we enhance the understanding of the complex nature of energy system transformations,facilitating a more holistic approach towards achieving sustainable and resilient energy transitions in emerging markets and beyond.

Crystal structure,phase transitions,and thermodynamic properties of magnesium metavanadate(MgV_(2)O_(6))

As a promising anode material for magnesium ion rechargeable batteries,magnesium metavanadate(MgV_(2)O_(6))has attracted considerable research interest in recent years.A MgV_(2)O_(6)sample was synthesized via a facile solid-state reaction by multistep-firing stoichiometric mixtures of MgO and V2O5 powder under an air atmosphere.The solid-state phase transition fromα-MgV_(2)O_(6)toβ-MgV_(2)O_(6)occurred at 841 K and the enthalpy change was 4.37±0.04 kJ/mol.The endothermic effect at 1014 K and the enthalpy change was 26.54±0.26 kJ/mol,which is related to the incongruent melting ofβ-MgV_(2)O_(6).In situ XRD was performed to investigate phase transition of the as-prepared MgV_(2)O_(6)at high temperatures.The cell parameters obtained by Rietveld refinement indicated that it crystallizes in a monoclinic system with the C2/m space group,and the lattice parameters of a=9.280 A°,b=3.501 A°,c=6.731 A°,β=111.76°.The solid-state phase transition fromα-MgV_(2)O_(6)toβ-MgV_(2)O_(6)was further studied by thermal kinetics,indicating that this process is controlled first by a fibril-like mechanism and then by a spherulitic-type mechanism with an increasing heating rate.Additionally,the enthalpy change of MgV_(2)O_(6)at high temperatures was measured utilizing the drop calorimetry,heat capacity was calculated and given as:Cp=208.3+0.03583T-4809000T^(−2)(298-923 K)(J mol^(−1)K^(−1)),the high-temperature heat capacity can be used to calculate Gibbs free energy of MgV_(2)O_(6)at high temperatures.

Investigation on Forbidden Lines of Magnetic Dipole Transitions 4p^(23)P_(1)-^(3)P_(0) in Rh^(13+)

Forbidden lines of highly charged ions(HCIs)have attracted attention for many years in various aspects.Magnetic dipole transition(M1)in the 4p^(23)P fine-structure manifold of Rh^(13+)was proposed as a candidate for the ultraprecise optical clock transition due to the low degeneracy of the clock levels and the suppression of relevant quadrupole shifts.Such transition possessing optical transitions with very narrow natural width and less susceptibility to external field perturbations.

Pressure-induced structural,electronic,and superconducting phase transitions in TaSe_(3)

TaSe_(3)has garnered significant research interests due to its unique quasi-one-dimensional crystal structure,which gives rise to distinctive properties.Using crystal structure search and first-principles calculations,we systematically investigated the pressure-induced structural and electronic phase transitions of quasi-one-dimensional TaSe_(3)up to 100 GPa.In addition to the ambient pressure phase(P2_(1)/m-I),we identified three high-pressure phases:P2_(1)/m-II,Pnma,and Pmma.For the P2_(1)/m-I phase,the inclusion of spin-orbit coupling(SOC)results in significant SOC splitting and changes in the band inversion characteristics.Furthermore,band structure calculations for the three high-pressure phases indicate metallic natures,and the electron localization function suggests ionic bonding between Ta and Se atoms.Our electron-phonon coupling calculations reveal a superconducting critical temperature of approximately 6.4 K for the Pmma phase at 100 GPa.This study provides valuable insights into the high-pressure electronic behavior of quasi-one-dimensional TaSe_(3).

Complete Universal Scaling in First-Order Phase Transitions

Phase transitions and critical phenomena are among the most intriguing phenomena in nature and society.They are classified into first-order phase transitions(FOPTs)and continuous ones.While the latter shows marvelous phenomena of scaling and universality,whether the former behaves similarly is a long-standing controversial issue.Here we definitely demonstrate complete universal scaling in field driven FOPTs for Langevin equations in both zero and two spatial dimensions by rescaling all parameters and subtracting nonuniversal contributions with singular dimensions from an effective temperature and a special field according to an effective theory.This offers a perspective different from the usual nucleation and growth but conforming to continuous phase transitions to study FOPTs.

Capacity planning of hydro-wind-solar hybrid power systems considering hydropower forbidden zones

In the capacity planning of hydro-wind-solar power systems(CPHPS),it is crucial to use flexible hydropower to complement the variable wind-solar power.Hydropower units must be operated such that they avoid specific restricted operation zones,that is,forbidden zones(FZs),to avoid the risks associated with hydropower unit vibration.FZs cause limitations in terms of both the hydropower generation and flexible regulation in the hydro-wind-solar power systems.Therefore,it is essential to consider FZs when determining the optimal wind-solar power capacity that can be compensated by the hydropower.This study presents a mathematical model that incorporates the FZ constraints into the CPHPS problem.Firstly,the FZs of the hydropower units are converted into those of the hydropower plants based on set theory.Secondly,a mathematical model was formulated for the CPHPS,which couples the FZ constraints of hydropower plants with other operational constraints(e.g.,power balance constraints,new energy consumption limits,and hydropower generation functions).Thirdly,dynamic programming with successive approximations is employed to solve the proposed model.Lastly,case studies were conducted on the hydro-wind-solar system of the Qingshui River to demonstrate the effectiveness of the proposed model.

New approach to measuring topological phase transitions utilizing Floquet technology

The Floquet technique provides a novel anomalous topological phase for non-equilibrium phase transitions.Based on the high symmetry of the quantum anomalous Hall model,the findings suggest a one-to-one correspondence between the average spin texture and the Floquet quasi-energy spectrum.A new approach is proposed to directly measure the quasienergy spectrum,replacing previous measurements of the average spin texture.Finally,we proposed a reliable experimental scheme based on ion trap platforms.This scheme markedly reduces the measurement workload,improves the measurement fidelity,and is applicable to multiple platforms such as cold atoms and nuclear magnetic resonance.

Metal-to-insulator transitions in 3d-band correlated oxides containing Fe compositions

Metal-to-insulator transitions (MITs),which are achieved in 3d-band correlated transitional metal oxides,trigger abrupt variations in electrical,optical,and/or magnetic properties beyond those of conventional semiconductors.Among such material families,iron(Fe:3d^(6)4s^(2))-containing oxides pique interest owing to their widely tunable MIT properties,which are associated with the various valence states of Fe.Their potential electronic applications also show promise,given the large abundance of Fe on Earth.Representative MIT properties triggered by critical temperature (TMIT) were reported for ReFe_(2)O_(4)(Fe^(2.5+)),ReBaFe_(2)O_(5)(Fe^(2.5+)),Fe_(3)O_(4)(Fe^(2.67+)),Re_(1/3)Sr_(2/3)FeO_(3)(Fe^(3.67+)),Re Cu_(3)Fe_(4)O_(12)(Fe^(3.75+)),and Ca_(1-x)Sr_(x)FeO_(3)(Fe^(4+))(where Re represents rare-earth elements).The common feature of MITs of these Fe-containing oxides is that they are usually accompanied by charge ordering transitions or disproportionation associated with the valence states of Fe.Herein,we review the material family of Fe-containing MIT oxides,their MIT functionalities,and their respective mechanisms.From the perspective of potentially correlated electronic applications,the tunability of the TMITand its resultant resistive change in Fe-containing oxides are summarized and further compared with those of other materials exhibiting MIT functionality.In particular,we highlight the abrupt MIT and wide tunability of TMITof Fe-containing quadruple perovskites,such as Re Cu3Fe4O12.However,their effective material synthesis still needs to be further explored to cater to potential applications.

Triple points and phase transitions of D-dimensional dyonic Ad S black holes with quasitopological electromagnetism in Einstein–Gauss–Bonnet gravity

By considering the negative cosmological constant Λ as a thermodynamic pressure, we study the thermodynamics and phase transitions of the D-dimensional dyonic Ad S black holes(BHs) with quasitopological electromagnetism in Einstein–Gauss–Bonnet(EGB) gravity. The results indicate that the small/large BH phase transition that is similar to the van der Waals(vdW) liquid/gas phase transition always exists for any spacetime dimensions. Interestingly, we then find that this BH system exhibits a more complex phase structure in 6-dimensional case that is missed in other dimensions.Specifically, it shows for D = 6 that we observed the small/intermediate/large BH phase transitions in a specific parameter region with the triple point naturally appeared. Moreover, when the magnetic charge turned off, we still observed the small/intermediate/large BH phase transitions and triple point only in 6-dimensional spacetime, which is consistent with the previous results. However, for the dyonic Ad S BHs with quasitopological electromagnetism in Einstein–Born–Infeld(EBI) gravity, the novel phase structure composed of two separate coexistence curves observed by Li et al. [Phys. Rev. D105 104048(2022)] disappeared in EGB gravity. This implies that this novel phase structure is closely related to gravity theories, and seems to have nothing to do with the effect of quasitopological electromagnetism. In addition, it is also true that the critical exponents calculated near the critical points possess identical values as mean field theory. Finally, we conclude that these findings shall provide some deep insights into the intriguing thermodynamic properties of the dyonic Ad S BHs with quasitopological electromagnetism in EGB gravity.

The forbidden transitions for magnesium isoelectronic sequences

Using the full relativistic quantum mechanics (GRASP2), we have calculated systematically the 3P 2- 3P 1 and 3P 1- 3P 0 magnetic dipole M1 energy level separations, transition probabilities and oscillator strengths in the 3s3p configuration of the magnesium sequences. The two configurations 3s3p and 3p3d are used. Breit and QED effects are treated as high-order perturbations. Excellent comparison is obtained throughout the range of atomic number Z, and the inclusion of the 3p3d configuration gives results which are in good agreements with recent experimental and reference data.

Simulation of mode transitions in capacitively coupled Ar/O_(2) plasmas

In this work,the effects of the frequency,pressure,gas composition,and secondary-electron emission coefficient on the discharge mode in capacitively coupled Ar/O_(2) plasmas were carefully studied through simulations.Three discharge modes,i.e.,α,γ,and drift-ambipolar(DA),were considered in this study.The results show that a mode transition from theγ-DA hybrid mode dominated by theγmode to the DA-αhybrid mode dominated by the DA mode is induced by increasing the frequency from 100 k Hz to 40 MHz.Furthermore,the electron temperature decreases with increasing frequency,while the plasma density first decreases and then increases.It was found that the electronegativity increases slightly with increasing pressure in the lowfrequency region,and it increases notably with increasing pressure in the high-frequency region.It was also observed that the frequency corresponding to the mode transition fromγto DA decreased when the secondary-electron emission coefficient was decreased.Finally,it was found that increasing the oxygen content weakens theγmode and enhances the DA mode.More importantly,the density of oxygen atoms and ozone will increase greatly with increasing oxygen content,which is of great significance for industrial applications.

Water Photomolecular Evaporation Due to Light-Mediated Ortho-Para Spin Transitions

Recent discoveries have revealed a groundbreaking phenomenon where light alone, without any thermal input, can induce water evaporation, termed the “photomolecular effect”. This study explores a novel hypothesis that this effect can be explained by ortho-para magnetic spin interactions in water molecules within the water-air interface layer. Water molecules, consisting of hydrogen and oxygen, exhibit different nuclear spin states: ortho-(triplet) and para-(singlet). The interaction of polarized light with these spin states may induce transitions between the rotational levels of ortho- and para-forms due to catalysts like triplet oxygen (O2) in its inhomogeneous magnetic field. Resonance pumping at 532 nm (~18,797 cm−1) due to the transition v1-v2-v3 ~ 0-8-2 (~18,796 cm−1) results in an increase in molecular energy sufficient to overcome intermolecular forces at the water surface, thereby causing evaporation. The proposed ortho-para conversion mechanism involves spin-orbit coupling and specific resonance conditions. This theory provides a quantum mechanical perspective on the photomolecular effect, potentially offering insights into natural processes such as cloud formation and climate modeling, as well as practical applications in solar desalination and industrial drying. Further experimental validation is required to confirm the role of spin interactions in light-induced water evaporation.

外源性碱性成纤维细胞生长因子促进大鼠创面愈合的机制

背景:深入揭示外源性碱性成纤维细胞生长因子促进创面愈合的分子机制。目的:探讨外源性碱性成纤维细胞生长因子对大鼠创面修复中巨噬细胞表型转换和肉芽再生的影响。方法:(1)体外细胞实验:分为正常对照组、低剂量碱性成纤维细胞生长因子组、高剂量碱性成纤维细胞生长因子组以及碱性成纤维细胞生长因子+丙戊酸组,其中低、高剂量碱性成纤维细胞生长因子组细胞培养基中分别添加100,200μg/L碱性成纤维细胞生长因子,碱性成纤维细胞生长因子+丙戊酸组细胞培养基中添加200μg/L碱性成纤维细胞生长因子和20 mmol/L Notch1/Jagged1激动剂丙戊酸。通过EdU实验、划痕实验、小管生成实验检测碱性成纤维细胞生长因子对人脐静脉内皮细胞增殖、迁移和血管新生的影响。(2)体内动物实验:SD大鼠按照随机数字表法分为模型组、低剂量碱性成纤维细胞生长因子组、高剂量碱性成纤维细胞生长因子组以及碱性成纤维细胞生长因子+丙戊酸组,构建大鼠全层皮肤缺损开放性创面模型,其中低、高剂量碱性成纤维细胞生长因子组皮下注射100,200μg/L碱性成纤维细胞生长因子,碱性成纤维细胞生长因子+丙戊酸组大鼠皮下注射200μg/L碱性成纤维细胞生长因子的同时腹腔注射10 mg/kg丙戊酸。给药7,14 d检测大鼠创面的愈合率;TUNEL检测创面组织中的细胞凋亡情况;酶联免疫吸附实验检测大鼠血清中丙二醛、超氧化物歧化酶、肿瘤坏死因子α和白细胞介素10水平;免疫荧光检测创面组织中巨噬细胞的表型转换情况;免疫组化检测创面组织中增殖细胞核抗原、CD31和血管内皮生长因子的表达;Western blot法检测创面组织中Notch1、Jagged1的表达。结果与结论:(1)与正常对照组相比,碱性成纤维细胞生长因子能明显促进人脐静脉内皮细胞的增殖、迁移和血管新生,并且具有剂量依赖性;(2)与模型组相比,碱性成纤维细胞生长因子能明显促进创面的愈合,下调创面组织中的细胞凋亡率;降低大鼠血清中丙二醛和肿瘤坏死因子α水平,升高超氧化物歧化酶和白细胞介素10水平;促使创面组织中巨噬细胞向M2型转换,上调创面组织中增殖细胞核抗原、CD31和血管内皮生长因子的表达;抑制创面组织中Notch1、Jagged1的表达,并且均具有剂量依赖性。丙戊酸可部分逆转碱性成纤维细胞生长因子对创面愈合的促进作用。结果表明,碱性成纤维细胞生长因子能明显促进创面愈合与肉芽再生以及诱导巨噬细胞向M2型转换,这可能与调控Notch1/Jagged1信号有关。

中国快速交通系统与旅游生态效率脱钩关系及时空格局演化

厘清快速交通系统与旅游生态效率发展的动态脱钩关系,对依托快速交通建设布局驱动旅游业高质量发展具有重要意义。论文基于2009—2020年中国省域面板数据,通过熵权法、旅游碳排放测算模型、Super-SBM模型测算快速交通系统和旅游生态效率的综合发展水平,采用Tapio脱钩模型和马尔科夫模型揭示二者脱钩关系的时空演化规律与状态转移特征。研究发现:(1)整体来看,中国快速交通系统发展水平呈现稳定增长态势,旅游生态效率则波动下降。(2)研究期内,省域和区域层次的脱钩关系均以强负脱钩为主。(3)省域主流脱钩关系呈现多种脱钩类型交替嬗变的时序演化特征,存在连接状态覆盖范围逐渐压缩、脱钩北上和负脱钩南下的空间转移趋向。(4)省域脱钩状态主要发生向“上”转移,负脱钩关系的稳定性最强且存在空间集聚倾向,不同脱钩状态的邻域对省域脱钩状态转移存在明显异质影响。

Phase transitions, micro-morphology and its oxidation mechanism in oxidation of ilmenite (FeTiO_3) powder

Phase transitions, morphology changes, and oxidation mechanism of the ilmenite oxidation process were investigated. FeTi03 transforms to hematite and rutile when oxidation at 700-800 ℃, and pseudobrookite is formed when the oxidation temperature reaches 900 ℃. The initial ilmenite powder exhibits paramagnetism; however, after being oxidized at the intermediate temperature （800-850 ℃）, the oxidation product exhibits weak ferromagnetism. The oxidation mechanism was discussed. The microstructure observations show that a lot of micro-pores emerge on the surfaces of ilmenite particles at the intermediate temperature, which is deemed to be caoable ofenhancin~ the mass transfer ofoxgen during oxidation.

Magnesium vapor nucleation in phase transitions and condensation under vacuum conditions

Recent findings related to coagulable magnesium vapor nucleation and growth in vacuum were assessed critically, with emphasis on understanding these processes at a fundamental molecular level. The effects of magnesium vapor pressure, condensation temperature, and condensation zone temperature gradient on magnesium vapor nucleation in phase transitions and condensation from atomic collision and coacervation with collision under vacuum conditions were discussed. Magnesium powder and magnesium lump condensates were produced under different conditions and characterized by scanning electron microscopy （SEM） and energy-dispersive X-ray spectroscopy （EDS）. The right condensation zone temperature approach to the liquid transition primarily improved the magnesium vapor concentration rate. The gas-solid phase transition was primarily inhibited by setting a small condenser temperature gradient. Under the right condensation temperature and temperature gradients, increasing magnesium vapor partial pressure improved crystallization and reduced the oxidation rate.