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1.
Proc Natl Acad Sci U S A ; 121(3): e2311486121, 2024 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-38207078

RESUMO

The ability to control the properties of twisted bilayer transition metal dichalcogenides in situ makes them an ideal platform for investigating the interplay of strong correlations and geometric frustration. Of particular interest are the low energy scales, which make it possible to experimentally access both temperature and magnetic fields that are of the order of the bandwidth or the correlation scale. In this manuscript, we analyze the moiré Hubbard model, believed to describe the low energy physics of an important subclass of the twisted bilayer compounds. We establish its magnetic and the metal-insulator phase diagram for the full range of magnetic fields up to the fully spin-polarized state. We find a rich phase diagram including fully and partially polarized insulating and metallic phases of which we determine the interplay of magnetic order, Zeeman-field, and metallicity, and make connection to recent experiments.

2.
Nature ; 583(7814): 48-54, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32572207

RESUMO

Observation of the neutrinoless double ß decay is the only practical way to establish that neutrinos are their own antiparticles1. Because of the small masses of neutrinos, the lifetime of neutrinoless double ß decay is expected to be at least ten orders of magnitude greater than the typical lifetimes of natural radioactive chains, which can mimic the experimental signature of neutrinoless double ß decay2. The most robust identification of neutrinoless double ß decay requires the definition of a signature signal-such as the observation of the daughter atom in the decay-that cannot be generated by radioactive backgrounds, as well as excellent energy resolution. In particular, the neutrinoless double ß decay of 136Xe could be established by detecting the daughter atom, 136Ba2+, in its doubly ionized state3-8. Here we demonstrate an important step towards a 'barium-tagging' experiment, which identifies double ß decay through the detection of a single Ba2+ ion. We propose a fluorescent bicolour indicator as the core of a sensor that can detect single Ba2+ ions in a high-pressure xenon gas detector. In a sensor made of a monolayer of such indicators, the Ba2+ dication would be captured by one of the molecules and generate a Ba2+-coordinated species with distinct photophysical properties. The presence of such a single Ba2+-coordinated indicator would be revealed by its response to repeated interrogation with a laser system, enabling the development of a sensor able to detect single Ba2+ ions in high-pressure xenon gas detectors for barium-tagging experiments.

3.
Phys Rev Lett ; 133(3): 032301, 2024 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-39094138

RESUMO

We present simulations of stochastic fluid dynamics in the vicinity of a critical endpoint belonging to the universality class of the Ising model. This study is motivated by the challenge of modeling the dynamics of critical fluctuations near a conjectured critical endpoint in the phase diagram of quantum chromodynamics (QCD). We focus on the interaction of shear modes with a conserved scalar density, which is known as model H. We show that the observed dynamical scaling behavior depends on the correlation length and the shear viscosity of the fluid. As the correlation length is increased or the viscosity is decreased we observe a crossover from the dynamical exponent of critical diffusion, z≃4, to the expected scaling exponent of model H, z≃3. We use our method to investigate the time-dependent correlation function of non-Gaussian moments M^{n}(t) of the order parameter. We find that the relaxation time depends in a nontrivial manner on the power n.

4.
Phys Rev Lett ; 132(24): 246505, 2024 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-38949372

RESUMO

We introduce a spin-symmetry-broken extension of the connected determinant algorithm [Riccardo Rossi, Determinant diagrammatic Monte Carlo algorithm in the thermodynamic limit, Phys. Rev. Lett. 119, 045701 (2017).PRLTAO0031-900710.1103/PhysRevLett.119.045701]. The resulting systematic perturbative expansions around an antiferromagnetic state allow for numerically exact calculations directly inside a magnetically ordered phase. We show new precise results for the magnetic phase diagram and thermodynamics of the three-dimensional cubic Hubbard model at half-filling. With detailed computations of the order parameter in the low to intermediate-coupling regime, we establish the Néel phase boundary. The critical behavior in its vicinity is shown to be compatible with the O(3) Heisenberg universality class. By determining the evolution of the entropy with decreasing temperature through the phase transition we identify the different physical regimes at U/t=4. We provide quantitative results for several thermodynamic quantities deep inside the antiferromagnetic dome up to large interaction strengths and investigate the crossover between the Slater and Heisenberg regimes.

5.
Arch Sex Behav ; 53(6): 2225-2236, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38514494

RESUMO

Gray et al.'s (2003) Sexual Fantasy Questionnaire (SFQ) is becoming an increasingly used self-report measure of sexual fantasy use. The current study analyzed the factorial structure and construct validity of the behavioral items of the SFQ using a nomological network of other sexuality-related measures in a large German-speaking sample (N = 846). Participants' (27.7% females) mean age was 30.8 years (SD = 11.0). Exploratory factor analysis revealed a 65-item scale comprising five-factors, which were termed: normophilic sexual fantasies, sexualized aggression, sexualized submission, submissive courtship, and bodily functions. This German version of the SFQ was found to have high construct validity indicated by its association with other related constructs. Based on these results, we argue that the SFQ is a valid self-report measure that can be used in both research and clinical practice (foremost the factors sexualized aggression and sexualized submission). Suggestions for future research are discussed in light of the results and the study's limitations.


Assuntos
Fantasia , Comportamento Sexual , Humanos , Feminino , Adulto , Masculino , Inquéritos e Questionários/normas , Comportamento Sexual/psicologia , Análise Fatorial , Reprodutibilidade dos Testes , Alemanha , Pessoa de Meia-Idade , Psicometria , Adolescente , Adulto Jovem , Autorrelato/normas
6.
Artigo em Inglês | MEDLINE | ID: mdl-38661511

RESUMO

BACKGROUND: There are conflicting data on a potential association between obesity and atopic dermatitis (AD). The purpose of this study was to investigate the relationship between obesity and AD disease severity. METHODS: Patients from the TREATgermany registry cohort were divided into three groups according to their body mass index (BMI). Due to low numbers, underweight patients (BMI <18.5 kg/m2) were excluded from the analysis. Physician- and patient-reported disease severity scores as well as additional phenotypic characteristics were evaluated for association with BMI. Generalized linear mixed models and multinomial logit models, respectively, were applied to investigate the association of BMI, age, sex and current systemic AD treatment with disease severity. RESULTS: This study encompassed 1416 patients, of which 234 (16.5%) were obese (BMI ≥30 kg/m2). Obesity was associated with lower educational background and smoking. Otherwise, obese and non-obese AD patients had similar baseline characteristics. Increased BMI was associated with higher oSCORAD (adjusted ß: 1.24, 95% CI: 1.05-1.46, p = 0.013) and Patient-oriented eczema measure (POEM) (adjusted ß: 1.09, 95% CI: 1.01-1.17, p = 0.038). However, the absolute difference in the overall oSCORAD was small between obese and non-obese AD patients (Δ oSCORAD = 2.5). Allergic comorbidity was comparable between all three groups, with the exception of asthma which was more pronounced in obese patients (p < 0.001). DISCUSSION: In this large and well-characterized AD patient cohort, obesity is significantly associated with physician- and patient-assessed measures of AD disease severity. However, the corresponding effect sizes were low and of questionable clinical relevance. The overall prevalence of obesity among the German AD patients was lower than in studies on other AD cohorts from different countries, which confirms previous research on the German population and suggests regional differences in the interdependence of AD and obesity prevalence.

7.
Sex Abuse ; 35(7): 863-895, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36720719

RESUMO

There are multiple ways to report risk scale results. Varela et al. (2014) found that Static-99R results were interpreted differently by prospective jurors based on risk level (high vs low) and an interaction between risk level and risk communication format (categorical, absolute estimate, and risk ratio). We adapted and extended Varela et al.'s (2014) study using updated Static-99R norms, recruiting a population-wide sample (n = 166), and adding variables assessing the personality factors 'cognitive motivation' (i.e., need for cognition) and 'attitudinal affect' (i.e., attitudes toward sex offenders, authoritarianism). We found a main effect of risk level and no effect of either communication format or the interaction between the two. Adding the personality variables increased explained variance from 9% to 34%, suggesting risk perception may be more about the personality of the person receiving the information than the information itself. We also found an interaction between attitudes toward sex offenders and risk level. Our results suggest risk perception might be better understood if personality factors are considered, particularly attitudes toward sex offenders. Because biases/personality of the person receiving the information are unknown in real world settings we argue that sharing multiple methods for communicating risk might be best and more inclusive.


Assuntos
Criminosos , Delitos Sexuais , Humanos , Medição de Risco/métodos , Criminosos/psicologia , Estudos Prospectivos , Delitos Sexuais/psicologia , Personalidade
8.
Chemistry ; 28(23): e202200881, 2022 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-35352413

RESUMO

Invited for the cover of this issue are Klaus Müller-Buschbaum and co-workers at Giessen University. The image depicts an aluminium-based MOF as a novel material for the capture of iodine radioisotopes from a potential gas atmosphere exposure. Read the full text of the article at 10.1002/chem.202104171.


Assuntos
Iodo , Cátions , Humanos , Iodetos , Metais
9.
Chemistry ; 28(23): e202104171, 2022 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-35179262

RESUMO

Eight cationic, two-dimensional metal-organic frameworks (MOFs) were synthesized in reactions of the group 13 metal halides AlBr3 , AlI3 , GaBr3 , InBr3 and InI3 with the dipyridyl ligands 1,2-di(4-pyridyl)ethylene (bpe), 1,2-di(4-pyridyl)ethane (bpa) and 4,4'-bipyridine (bipy). Seven of them follow the general formula 2 ∞ [MX2 (L)2 ]A, M=Al, In, X=Br, I, A- =[MX4 ]- , I- , I3 - , L=bipy, bpa, bpe. Thereby, the porosity of the cationic frameworks can be utilized to take up the heavy molecule iodine in gas-phase chemisorption vital for the capture of iodine radioisotopes. This is achieved by switching between I- and the polyiodide I3 - in the cavities at room temperature, including single-crystal-to-single-crystal transformation. The MOFs are 2D networks that exhibit (4,4)-topology in general or (6,3)-topology for 2 ∞ [(GaBr2 )2 (bpa)5 ][GaBr4 ]2 ⋅bpa. The two-dimensional networks can either be arranged to an inclined interpenetration of the cationic two-dimensional networks, or to stacked networks without interpenetration. Interpenetration is accompanied by polycatenation. Due to the cationic character, the MOFs require the counter ions [MX4 ]- , I- or I3 - counter ions in their pores. Whereas the [MX4 ]- , ions are immobile, iodide allows for chemisorption. Furthermore, eight additional coordination polymers and complexes were identified and isolated that elaborate the reaction space of the herein reported syntheses.

10.
Chemistry ; 27(67): 16634-16641, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34613634

RESUMO

Homoleptic, 3D coordination polymers of the formula 33 ∞ [Ln(3-PyPz)3 ] and 3 ∞ [Ln(4-PyPz)3 ], (3-PyPz)- =3-(3-pyridyl)pyrazolate anion, (4-PyPz)- =3-(4-pyridyl)pyrazolate anion, both C8 H6 N3 - , Ln=Sm, Eu, Gd, Tb, Dy, were obtained as highly luminescent frameworks by reaction of the lanthanide metals (Ln) with the aromatic heterocyclic amine ligands 3-PyPzH and 4-PyPzH. The compounds form two isotypic series of 3D coordination polymers and exhibit fair thermal stability up to 360 °C. The luminescence properties of all ten compounds were determined in the solid state, with an antenna effect through ligand-metal energy transfer leading to high efficiency of the luminescence displayed by good quantum yields of up to 74 %. The emission is mainly based on ion-specific lanthanide-dependent intra 4 f-4 f transitions for Tb3+ : green, Dy3+ : yellow, Sm3+ : orange-red, Eu3+ : red. For the Gd3+ -containing compounds, the yellow emission of ligand triplet-based phosphorescence is observed at room temperature and 77 K. Co doping of the Gd-containing frameworks with Eu3+ and Tb3+ allow further shifting of the chromaticity towards white light emission.

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