The Influence of Physical Exercise Frequency and Intensity on Individual Entrepreneurial Behavior: Evidence from China.

Physical exercise can benefit individuals' physical and mental health and also influence individuals' long-term behavioral choices. Doing exercise is particularly important given that physical exercise can impact individuals' cognitive abilities and positive emotional states, which may further impact entrepreneurial behavior. Therefore, understanding the relationship between exercise and entrepreneurial behavior is essential, because it can provide policy suggestions for popularizing athletic activities and boosting entrepreneurship. Consequently, the present study examined whether physical exercise could predict entrepreneurial behavior and the possible psychological mechanisms within this relationship. Based on the 2017 Chinese General Social Survey (CGSS2017), this study tested the hypotheses using the Probit and Tobit models. The results showed that individuals' physical exercise intensity and frequency positively affected their entrepreneurial behavior. In addition, five variables moderated the relationships between physical exercise and individual entrepreneurial behavior: urban-rural differences, education level, marital status, the existence of minor children, and age. Moreover, positive emotions and physical/mental health mediated the influence of physical exercise (exercise frequency and exercise intensity) on individual entrepreneurial behavior. Endogeneity explanations were ruled out by including instrumental variable, copula terms and adopting coarsened exact matching.

Using Extended Technology Acceptance Model to Assess the Adopt Intention of a Proposed IoT-Based Health Management Tool.

Advancements in IoT technology contribute to the digital progress of health science. This paper proposes a cloud-centric IoT-based health management framework and develops a system prototype that integrates sensors and digital technology. The IoT-based health management tool can collect real-time health data and transmit it to the cloud, thus transforming the signals of various sensors into shared content that users can understand. This study explores whether individuals in need tend to use the proposed IoT-based technology for health management, which may lead to the new development of digital healthcare in the direction of sensors. The novelty of this research lies in extending the research perspective of sensors from the technical level to the user level and explores how individuals understand and adopt sensors based on innovatively applying the IoT to health management systems. By organically combining TAM with MOA theory, we propose a comprehensive model to explain why individuals develop perceptions of usefulness, ease of use, and risk regarding systems based on factors related to motivation, opportunity, and ability. Structural equation modeling was used to analyze the online survey data collected from respondents. The results showed that perceived usefulness and ease of use positively impacted adoption intention, Perceived ease of use positively affected perceived usefulness. Perceived risk had a negative impact on adoption intention. Readiness was only positively related to perceived usefulness, while external benefits were positively related to perceived ease of use and negatively related to perceived risk. Facilitative conditions were positively correlated with perceived ease of use and negatively correlated with perceived risk. Technical efficacy was positively related to perceived ease of use and perceived usefulness. Overall, the research model revealed the cognitive mechanism that affects the intention of individuals to use the system combining sensors and the IoT and guides the digital transformation of health science.

The Influence of Psychological Safety on Students' Creativity in Project-Based Learning: The Mediating Role of Psychological Empowerment.

Creative-oriented new educational model will shape the direction and appearance of world development. This study focuses on the role of psychological safety and psychological empowerment in improving students' creativity in the context of project-based learning from the perspective of student empowerment. Based on self-determination theory, we propose that psychological safety positively affects students' creativity through psychological empowerment, and fault-tolerant culture plays a positive role in it. In this study, 238 students who participated in project-based learning were randomly selected to conduct a questionnaire survey. The results show that there is a positive correlation between psychological safety and creativity, and psychological empowerment plays an intermediary role in the relationship between them. The fault-tolerant culture enhances the direct influence of psychological safety on psychological empowerment and the indirect influence of psychological safety on creativity. Theoretical and practical implications were also discussed.

Retraction of "Solid-to-Solid Crystallization of Organic Thin Films: Classical and Nonclassical Pathways".

[This retracts the article DOI: 10.1021/acsomega.8b00153.].

Solid-to-Solid Crystallization of Organic Thin Films: Classical and Nonclassical Pathways.

The solid-to-solid crystallization processes of organic molecules have been poorly understood in view of the complexity and the instability of organic crystals. Here, we studied the crystallization of a π-conjugated small molecular semiconductor, bis-(8-hydroxyquinoline) copper (CuQ2), by annealing the thin films at different temperatures. We observed a classical film-to-nanorods crystallization at 80 °C, a coexistence of classical and nonclassical nucleation and particle growth at 120 °C, and a nonclassical crystal growth at 150 °C. We found that the growth of the crystals followed the following processes: particle nucleation, particle growth, particle migration, nondirectional particle attachment, and structure reconstruction. We notice that the growth of CuQ2 particles follows an outside-to-inside process. More interestingly, our experiments suggest that the submicron CuQ2 particles are able to migrate dozens of micrometers at 150 °C.

Electronic structures of in-plane two-dimensional transition-metal dichalcogenide heterostructures.

Electronic structures of in-plane two-dimensional transition-metal dichalcogenide (TMD) heterostructures have been studied on the basis of the first-principles density functional calculations. In contrast to vertically stacked TMD heterostructures, true type-II band alignment could be established in in-plane TMD heterostructures due to their coherent lattice and strong electronic coupling, and thus leads to the efficient separation of electrons and holes. In in-plane TMD heterostructures interfaced along the zigzag direction, electronic reconstruction causes band bending in constituent TMDs, unveiling the great potential in achieving high efficiency of water splitting and constructing Schottky barrier solar cells. In addition, type-I alignment could also be demonstrated in in-plane TMD heterostructures, enriching the photoluminescence features of TMD materials. In-plane TMD heterostructures with the ultimate thickness limit for semiconductor heterostructures will definitely spark a surge in research activity.

Phase-sensitive Bloch surface wave sensor based on variable angle spectroscopic ellipsometry.

In this paper, we propose a phase-sensitive Bloch surface wave sensor based on the variable angle spectroscopic ellipsometry and numerically simulate the phase behavior of the sensor. The simulation results show that the dependence of resonant phase is step-like when BSWs are excited. In contrast to the reflectance behavior, even though losses of the dielectric layers are very small, the resonance dip in the reflectivity will be shallow while the step-like change of the reflection phase of the BSW still be remarkable. This means that phase detection is an alternative to reflectivity intensity detection for the sensing applications of the BSWs in this case. Our experimental results indicate that phase detection for the BSW sensors has the potential to achieve the higher sensitivity and the lower limit of detection.

Graphene/g-C3N4 bilayer: considerable band gap opening and effective band structure engineering.

The layered graphene/g-C3N4 composites show high conductivity, electrocatalytic performance and visible light response and have potential applications in microelectronic devices and photocatalytic technology. In the present work, the stacking patterns and the correlations between electronic structures and related properties of graphene/g-C3N4 bilayers are investigated systematically by means of first-principles calculations. Our results indicate that the band gap of graphene/g-C3N4 bilayers can be up to 108.5 meV, which is large enough for the gap opening at room temperature. The calculated charge density difference unravels that the charge redistribution drives the interlayer charge transfer from graphene to g-C3N4. Interestingly, the investigation also shows that external electric field can tune the band gap of graphene/g-C3N4 bilayers effectively. Our research demonstrates that graphene on g-C3N4 with a tunable band gap and high carrier mobility may provide a novel way for fabricating high-performance graphene-based nanodevices.

Dynamics simulation of the interaction between serine and water.

Using the first principles density functional theory (DFT), we simulated the neutron scattering spectra of the hydration dynamics of serine. Experimental data analyses have shown that dissociative H2O molecules were more likely to form hydrogen bonds (H-bonds) with an -OH group in monohydrated serine and easily shift to a -NH3 (+) group at a higher hydration level [P. Zhang, Y. Zhang, S. H. Han, Q. W. Yan, R. C. Ford, and J. C. Li, J. Phys. Chem. A 110, 5000 (2006)]. We set the 1:1 ratio hydrated compounds at the two positions and found that the H2O could be optimized to form H-bonds with -OH and -NH3 (+) separately. When the simulated phonon signals of the -OH···H2O and -NH3(+)···H2O combinations were summed on a 3:1 scale, the calculating spectra were in good agreement with the experimental results, especially for the peak at 423 cm(-1) of the -OH···H2O combination and the peak at 367 cm(-1) of the -NH3(+)···H2O combination, which mutually complemented the real spectrum. We confirm that H2O may break the intermolecular H-bonds of the interlaced binding -OH to form a new structure, and that with the skeleton deformation of serine, H2O forms stronger H-bonds more often with the -NH3 (+) side indicating the flexible dynamic mechanism of the serine hydration process.

Realization of tunable Dirac cone and insulating bulk states in topological insulators (Bi(1-x)Sb(x))(2)Te(3).

The bulk-insulating topological insulators with tunable surface states are necessary for applications in spintronics and quantum computation. Here we present theoretical evidence for modulating the topological surface states and achieving the insulating bulk states in solid-solution (Bi(1-x)Sb(x))(2)Te(3). Our results reveal that the band inversion occurs in (Bi(1-x)Sb(x))(2)Te(3), indicating the non-triviality across the entire composition range, and the Dirac point moves upwards till it lies within the bulk energy gap accompanying the increase of Sb concentration x. In addition, with increasing x, the formation of prominent native defects becomes much more difficult, resulting in the truly insulating bulk. The solid-solution system is a promising way of tuning the properties of topological insulators and designing novel topologically insulating devices.

Structure and electronic properties and phase stabilities of the Cd(1-x)Zn(x)S solid solution in the range of 0≤x≤1.

As an excellent bandgap-engineering material, the Cd(1-x)Zn(x)S solid solution, is found to be an efficient visible light response photocatalyst for water splitting, but few theoretical studies have been performed on it. A better characterization of the composition dependence of the physical and optical properties of this material and a thorough understanding of the bandgap-variation mechanism are necessary to optimize the design of high-efficience photocatalysts. In order to get an insight into these problems, we systematically investigated the crystal structure, the phase stability, and the electronic structures of the Cd(1-x)Zn(x)S solid solution by means of density functional theory calculations. The most energetically favorable arrangement of the Cd, Zn, S atoms and the structural disorder of the solid solution are revealed. The phase diagram of the Cd(1-x)Zn(x)S solid solution is calculated based on regular-solution model and compared with the experimental data. This is the first report on the calculated phase diagram of this solid solution, and can give guidance for the experimental synthesis of this material. Furthermore, the variation of the electronic structures versus x and its mechanism are elaborated in detail, and the experimental bandgap as a function of x is well predicted. Our findings provide important insights into the experimentally observed structural and electronic properties, and can give theoretical guidelines for the further design of the Cd(1-x)Zn(x)S solid solution.

Structure of Co-Doped Alq3 thin films investigated by grazing incidence X-ray absorption fine structure and Fourier transform infrared spectroscopy.

The structural properties of Co-doped tris(8-hydroxyquinoline)aluminum (Alq(3)) have been studied by grazing incidence X-ray absorption fine structure (GIXAFS) and Fourier transform infrared spectroscopy (FTIR). GIXAFS analysis suggests that there are multivalent Co-Alq(3) complexes and the doped Co atoms tend to locate at the attraction center with respect to N and O atoms and bond with them. The FTIR spectra indicate that the Co atoms interact with the meridional (mer) isomer of Alq(3) rather than forming inorganic compounds.

Codoping synergistic effects in N-doped SrTiO(3) for higher energy conversion efficiency.

To understand the codoping synergistic effects in metal oxide semiconductors with wide band gaps as photocatalysts, we chose N-doped SrTiO(3) as a host to determine the effects of some nonmetal and metal codopants on it by performing the first-principles calculations for N/H-, N/X- (X = F, Cl, Br, I), N/M(1)- (M(1) = V, Nb, Ta) and N/M(2)- (M(2) = Sc, Y, La) codoped SrTiO(3). Our study shows that the codoping of N with nonmetal atoms H, F and all metal atoms except Ta can reduce the energy cost of N doping and thus improve the solubility of N in SrTiO(3). Octahedra in codoped SrTiO(3) suffer from a relative larger distortion than that of N-doped SrTiO(3) and the distorted octahedra can generate a more efficient internal field, which can promote the separation and reduce the recombination of electron-hole pairs, due to the nonzero dipole moment of distorted octahedra. In the codoped structures, compensating vacancy defects can be avoided and narrowed band gaps without recombination centers (oxygen vacancies) can be realized (except the N/Sc-codoped SrTiO(3) that shows a wider band gap than the pristine SrTiO(3)). The N related defect acceptor can be passivated resulting from electron transfer from donor to acceptor (DAP recombination). As photocatalysts, these defective-less codoped systems with narrowed band gaps should manifest high energy conversion efficiency under visible light irradiation. One should consider this passivated donor/acceptor dopants-codoping approach for exploiting new available visible light-driven photocatalysts.

Theoretical study of N-doped TiO2 rutile crystals.

The N-doping effects on the electronic and optical properties of TiO2 rutile crystal have been studied using density functional theory (DFT). The calculations of several possible N-doped structures show that band gaps have little reduction but some N 2p states lie within the band gap in the substitutional N to O structure and interstitial N-doped rutile supercell, which results in the reduction of the photon-transition energy and absorption of visible light. In contrast, substitutional N to Ti doped model has a significant band-gap narrowing. The results maybe clarify confusions in nitrogen-doped TiO2 rutile crystal.

Vibrational spectroscopic studies of the interaction of water with serine.

The vibrational dynamics of water around serine was investigated by using Raman spectroscopy and inelastic incoherent neutron scattering. Experiments with serine in deuterium oxide were performed to assist the assignment. The study shows that for the serine, the exchange of protons-deuterons on the active -NH3+ and -OH groups were relatively easy, whereas there were hardly any exchanged on the -CH or -CH2- groups. The main features of the spectra for hydrated samples (versus the dry samples) were altered considerably; new sharp peaks in the measured spectra appeared, indicating that the hydrogen bonding between water and serine had disturbed the structure of the serine molecule.

Inelastic neutron scattering studies of the interaction between water and some amino acids.

The interaction between water and some of amino acids (glycine, L-glutamine, L-threonine, L-cysteine and L-serine) was studied by inelastic incoherent neutron scattering (IINS). The vibrational spectra of dry amino acids and amino acids with a water content (e.g., 1 mol water/1 mol amino acid) were recorded. Comparing the difference spectra obtained by subtracting the spectrum of dry sample from those of wet sample with the spectra of ice Ih, we obtained that the difference spectrum for serine changed greatly from normal ice spectrum; but on the other hand, the difference spectra for the other amino acids such as glycine, glutamine, threonine, and cysteine changed slightly. The results demonstrate that serine has stronger hydrophilic character than glycine, glutamine, threonine, and cysteine. This is the first time the hydrophilic or hydrophobic character of amino acids was studied by using inelastic neutron scattering techniques, which provides important information for theoretical modeling and force field refinement for the interaction between water and the amino acids studied here.