Search

Photoionization spectroscopy and mass spectrometry of doped helium (He) nanodroplets rely on the ability to efficiently detect ions and/or electrons. Using a commercial quadrupole mass spectrometer and a photoelectron–photoion coincidence spectrometer, we systematically measure yields of ions and electrons created in pure and doped He nanodroplets in a wide size range and in two ionization regimes—direct ionization and secondary ionization after resonant photoexcitation of the droplets. For two different types of dopants (oxygen molecules, O2, and lithium atoms, Li), we infer the optimal droplet size to maximize the yield of ejected ions. When dopants are ionized by charge-transfer to photoionized He nanodroplets, the highest yield of O2 and Li ions is detected for a mean size of ∼ 5 × 1 0 4 He atoms per nanodroplet. When dopants are Penning ionized via photoexcitation of the He droplets, the highest yield of O2 and Li ions is detected for ∼ 1 0 3 and ∼ 1 0 5 He atoms per droplet, respectively. At optimum droplet sizes, the detection efficiency of dopant ions in proportion to the number of primary photoabsorption events is up to 20% for charge-transfer ionization of O2 and 2% for Li, whereas for Penning ionization it is 1% for O2 and 4% for Li. Our results are instrumental in determining optimal conditions for mass spectrometric studies and photoionization spectroscopy of molecules and complexes isolated in He nanodroplets. [ABSTRACT FROM AUTHOR]

Introduction: Physical exercise is considered a useful non-pharmacological adjunctive treatment for promoting recovery from substance use disorders (SUD). However, adherence to physical exercise treatments is low, and little is known about what factors are associated with the initiation and maintenance of physical exercise behaviors. The aim of this study was to explore the psychosocial factors underlying these behaviors in individuals with SUD using an integrated theoretical model based on the health action process approach (HAPA) and the theory of planned behavior (TPB). Methods: A total of 1,197 individuals with SUDs (aged 37.20  ±  8.62  years) were recruited from 10 compulsory isolation drug rehabilitation centers in Zhejiang Province via convenience sampling according to a set of inclusion criteria. Selfreported data were collected to assess task self-efficacy (TSE), maintenance self-efficacy (MSE), recovery self-efficacy (RSE), outcome expectations (OE), action planning (AP), coping planning (CP), social support (SS), subjective norms (SN), attitude behavior (AB), behavioral intention (BI), perceived behavioral control (PBC), risk perception (RP), exercise stage, and exercise behavior in this integrated model. ANOVA and structural equation modeling (SEM) were used to evaluate this model. Results: One-way ANOVA revealed that the majority of the moderating variables were significantly different in the exercise phase. Further SEM showed that the model fit the data and revealed several important relationships. TSE, RP, SS, AB, and SN were indirectly associated with physical exercise behavior in individuals with SUD through the BI in the SUD initiation stage. In addition, PBC was directly related to physical exercise behavior in individuals with SUD. In the maintenance stage, MSE, AP, CP and exercise behavior were significantly related. Moreover, AP and CP were mediators of BI and MSE. Conclusion: This study is the first attempt to integrate patterns of physical exercise behavior in individuals with SUD. The HAPA-TPB integration model provides a useful framework for identifying determinants of physical exercise behavioral intentions and behaviors in individuals with SUD and for explaining and predicting the initiation and maintenance of physical exercise behaviors in these individuals. Moreover, the model provides scientific guidance for the enhancement of physical exercise adherence in individuals with SUD. [ABSTRACT FROM AUTHOR]

Introduction: Psychological research has shown that, among other variables, affective state, expectancy, and behavioral intention influence whether or not a (physically active) behavior is performed. Environmental effects during physical activity on affective state have been well studied; however, research regarding environmental effects on expectancy or intention is limited. Sport climbing is a form of physical activity that is performed both indoors and outdoors and is therefore considered as suitable to study environmental effects. Therefore, the aim of the present study was to investigate environmental effects during sport climbing on affective state, expectancy, and intention. The nature of the relationship between some of these parameters should also be explored. Methods: Using a within-subjects design, 48 participants were to climb both once indoors in a climbing gym and once outdoors at a crag. The design included questionnaire-based surveys at multiple time points. Affective state, expectancy, and behavioral intention were measured at different test time points. Results: Two-factor repeated-measures ANOVAs revealed significant main effects of the factors environment (indoor - outdoor) and time (T1 - T2 - T3) for affective state, indicating more positive affective state during outdoor climbing. No environment*time interactions were found. Furthermore, significantly higher intention (d = 0.32; p = 0.032) was measured after the outdoor condition (M = 32.5, SD = 4.1) compared to the indoor condition (M = 31.2, SD = 4.7). Multiple linear regressions revealed that expectancies (measured before and after the session) significantly predicted post-climbing intention only indoors. Conclusion: The results at least partly suggest environmental effects on behaviorally relevant variables during climbing. Outdoor climbing might provide more favorable characteristics for physically active behavior compared to indoor climbing. Health psychologists or public health professionals who focus on increasing physical activity for their clients could recommend outdoor climbing over indoor climbing. [ABSTRACT FROM AUTHOR]

Brief exercise bouts can have positive effects on the affective state, which in turn could affect the intention for future exercise. Such benefits may be enhanced by manipulating expectations. The aim of this study was to examine whether the affective state after physical activity or the intention for future exercise can be influenced by manipulating expectations. Furthermore, the relationship between affect and intention was investigated. In an online experiment, 121 persons completed either a 10-minute workout (PA), a workout after manipulation of expectations (PA + EM), or a control intervention (CG) after randomized group allocation. Data on affective state, expectations, and intention were collected before and after the intervention using questionnaires. After intervention, PA groups showed significantly more positive values than CG in several affective parameters, in other affective parameters, only PA + EM differed from CG. Affect was positively associated with intention alongside outcome expectations. No difference was found in intention. Although no significant effects of expectation manipulation on affective state or intention were found, latent effects cannot be ruled out. Further exploration of the importance of word choice in describing physical activity in the context of interventions to increase physical activity is necessary. Here, affect should be considered., (© 2024 The Author(s). Applied Psychology: Health and Well‐Being published by John Wiley & Sons Ltd on behalf of International Association of Applied Psychology.)

Non‐oxidative coupling of methane is a promising route to obtain ethylene directly from natural gas. We synthesized siliceous [Fe]zeolites with MFI and CHA topologies and found that they display high selectivity (>90 % for MFI and >99 % for CHA) to ethylene and ethane among gas‐phase products. Deactivated [Fe]zeolites can be regenerated by burning coke in air. In situ X‐ray absorption spectroscopy demonstrates that the isolated Fe3+ centers in zeolite framework of fresh catalysts are reduced during the reaction to the active sites, including Fe2+ species and Fe (oxy)carbides dispersed in zeolite pores. Photoelectron photoion coincidence spectroscopy results show that methyl radicals are the reaction intermediates formed upon methane activation. Ethane is formed by methyl radical coupling, followed by its dehydrogenation to ethylene. Based on the observation of intermediates including allene, vinylacetylene, 1,3‐butadiene, 2‐butyne, and cyclopentadiene over [Fe]MFI, a reaction network is proposed leading to polyaromatic species. Such reaction intermediates are not observed over the small‐pore [Fe]CHA, where ethylene and ethane are the only gas‐phase products. [ABSTRACT FROM AUTHOR]

Survivors of breast cancer are an important target for health promotion interventions, and physical activity (PA) is recommended with benefits being well established. More and more behavior theory guided interventions are planned and tailored to the individuals, targeting specifics needs and personal characteristics. We aimed to test the effectiveness of two behavior change techniques [coping planning (CP) and self-monitoring (SM)] for promoting PA in survivors of breast cancer, using a single-case design. In a powerful multiple sample N -of-1 RCT, 10 women post-breast cancer (M = 52.8 years) were randomly assigned to four experimental conditions (CP and/or SM, control) for 60 days and their daily step count was observed. The overall effects were analyzed using multilevel time-series with random intercepts. Time-series regression models and supplementary pairwise analyses were conducted for individuals. Multilevel analyses showed significant effects of CP and SM. Single-case analyses showed that six participants walked significantly more on the intervention days, that combined interventions were effective for five participants, but two participants had better results with the other two conditions. Combined self-regulatory techniques were more effective in promoting PA however, individual variability should be considered in future studies with survivors of breast cancer. Retrospectively registered: https://osf.io/eakjy/?view%5fonly=81bf3dc084a0410a8ea28265e0f3c360 , 31-01-2023.(raise query) [ABSTRACT FROM AUTHOR]

Integrated Pest Management (IPM) is one of the important components to reduce the use of pesticides and their risk to farmers. This study aimed to determine the factors influencing IPM usage to reduce pesticide use by greenhouse farmers based on the Health Action Process Approach (HAPA). A total of 300 farmers from Jiroft, Kerman Province, Iran, participated in this cross-sectional study using multi-stage sampling, in 2021. The data collection tool was a questionnaire including demographic information, status of the use of IPM, and HAPA constructs regarding IPM (risk perception, outcome expectancies, task self-efficacy, action planning, coping planning, recovery self-efficacy, and maintenance self-efficacy), of which psychometric properties were examined and approved. Kruskal-Wallis test and Structural Equation Modeling (SEM) were used to analyze the data. There was a significant correlation between action planning (r= 0.29), coping planning (r= 0.33), maintenance self-efficacy (r= 0.23), and recovery self-efficacy (r= 0.23) with IPM. SEM revealed a direct and significant relationship between task selfefficacy, maintenance self-efficacy, coping planning, and recovery self-efficacy with IPM. HAPA is suggested to be used as a framework for interventions aiming at increasing application of IPM and lower pesticide use in agriculture. [ABSTRACT FROM AUTHOR]

Results from the application of optical potential, relativistic optical potential, relativistic convergent close-coupling, and binary encounter Bethe models to electron scattering from gas-phase cadmium are presented. In particular, integral cross sections for elastic scattering, summed discrete electronic-state excitation, and ionization scattering processes are reported over an extended incident electron-energy range. Total cross sections are constructed by taking their sum. Measurements are presented for elastic scattering and for excitation to the 51P1 state. The theoretical and experimental results are compared to previous calculations and measurements. Recommended electron cross-section datasets are constructed over an incident electron energy range of 0.01–10 000 eV. [ABSTRACT FROM AUTHOR]

The coronavirus pandemic has influenced many lives, particularly older adults'. Although isolation protects from infection, health behaviors like physical activity (PA) are important to reinstate after lockdown. However, fear of Covid‐19 may act as a barrier, for example, by preventing people from going outside. Based on the health action process approach (HAPA), we investigated whether and why older adults' PA changed after lockdown, and whether fear of Covid‐19 moderates the intention–behavior relationship. Participants of this longitudinal study aged 65+ from German‐speaking Europe completed an online questionnaire about their PA, fear of Covid‐19, and HAPA factors in April and May 2020. Data were analyzed using multiple linear regressions. Results showed that moderate to vigorous activity (MVPA) remained stable after lockdown and that self‐efficacy most robustly influenced the intention to be active. PA was not explained by any volitional factor but was strongly related to past PA. Interestingly, the relationship of past and future MVPA was attenuated by fear of Covid‐19, but this finding was not robust when outliers were removed. In conclusion, self‐efficacy is the most important motivator for PA in older adults after an interruption like a lockdown. Strong physical activity habits may facilitate PA after a period of isolation. [ABSTRACT FROM AUTHOR]

Although CH 2 FCl (HCFC-31) recently became of great atmospheric importance, studies concerning its excited states are almost nonexistent. Several excited singlet states were studied (valence nσ* and Rydberg n3s, n3p, σ3s, and σ3p) through highly correlated multireference configuration interaction with singles and doubles, including extensivity correction. Comparison with the states of CH 3 Cl indicates a strong influence of the F atom. Potential energy curves suggest formation of an electrostatically bound complex that relaxes to a hydrogen-bonded contact ion-pair (HBCIP) which can decay yielding CH 2 F + Cl or to the ground state minimum of CH 2 FCl. The HBCIP has a dipole moment of 9.57 D, a CI wavefunction described as 0.65ionic + 0.20biradical and it is strongly bonded by 4.72 eV. Its H bond has characteristics of moderate and strong H bonds. The simulated absorption spectrum confirms the nσ* assignment for the first and suggests the n3s + n3p σ assignment for the second band., (© 2023 Wiley Periodicals LLC.)

Nanofiber is a kind of high‐performance material, which has great applications. Among many preparation methods, centrifugal electrospinning combines the advantages of electrospinning and centrifugal spinning, with high yield and a wide range of application. But its influencing factors are numerous, the process is still immature, and unable to meet the needs of industrialization. Here, we design a set of centrifugal electrospinning equipment and its process, and explore the influence of rotor form on fiber formation. First, the structure and working principle of experimental equipment of centrifugal electrospinning are introduced. Then, the influence of two factors, the rotor shape and rotor material, on space electric field is studied through theoretical and simulation analysis. Finally, based on the designed equipment, the effects of different rotor forms on the fibers preparation of centrifugal electrospinning are studied. The results show that the fiber diameter of centrifugal electrospinning is greatly affected by the form of the rotor. By changing the surface shape of the rotor and the rotor material, the diameter of the fiber can be controlled. Experiments show that the average fiber diameter of the γ‐shaped rotor is the smallest, and the fiber spun with ULTEM PEI 1010 material has the best overall performance. [ABSTRACT FROM AUTHOR]

As physical exercise benefits both physical and psychological health of college students, it is important to promote the habit of physical exercise among them. This study adopted the Health Action Process Approach (HAPA) model to understand the exercise intention–action link and determine the moderating role of self-efficacy. We recruited 242 students from a university in China and asked them to complete a six-wave survey. The survey results indicated that exercise intention was positively related to both coping planning and action planning, which pave the way to performing the action of exercise. However, such mediation effects varied under conditions of self-efficacy. Participants with high self-efficacy exhibited stronger relationships between intention and planning, and between planning and action. The study results suggest that planning has a time-lagged mediation effect in the relationship between intention and action. Additionally, the findings shed light on the moderating role of self-efficacy, which can be useful in developing health-promotion strategies for college students. [ABSTRACT FROM AUTHOR]

The reactivity, energetics and dynamics of bimolecular reactions between S2+ and three neutral species (Ar, H2 and N2) have been studied using a position-sensitive coincidence methodology at centre-of-mass collision energies below 6 eV. This is the first study of bimolecular reactions involving S2+, a species detected in planetary ionospheres, the interstellar medium, and in anthropogenic manufacturing processes. The reactant dication beam employed consists predominantly of S2+ in the ground 3P state, but some excited states are also present. Most of the observed reactions involve the ground state of S2+, but the dissociative electron transfer reactions appear to exclusively involve excited states of this atomic dication. We observe exclusively single electron-transfer between S2+ and Ar, a process which exhibits strong forward scatting typical of the Landau–Zener style dynamics observed for other dicationic electron transfer reactions. Following collisions between S2+ + H2, non-dissociative and dissociative single electron-transfer reactions were detected. The dynamics here show evidence for the formation of a long-lived collision complex, [SH2]2+, in the dissociative single electron-transfer channel. The formation of SH+ was not observed. In contrast, the collisions of S2+ + N2 result in the formation of SN+ + N+ in addition to the products of single electron-transfer reactions. [ABSTRACT FROM AUTHOR]

Non-oxidative coupling of methane is a promising route to obtain ethylene directly from natural gas. We synthesized siliceous [Fe]zeolites with MFI and CHA topologies and found that they display high selectivity (>90 % for MFI and >99 % for CHA) to ethylene and ethane among gas-phase products. Deactivated [Fe]zeolites can be regenerated by burning coke in air. In situ X-ray absorption spectroscopy demonstrates that the isolated Fe 3+ centers in zeolite framework of fresh catalysts are reduced during the reaction to the active sites, including Fe 2+ species and Fe (oxy)carbides dispersed in zeolite pores. Photoelectron photoion coincidence spectroscopy results show that methyl radicals are the reaction intermediates formed upon methane activation. Ethane is formed by methyl radical coupling, followed by its dehydrogenation to ethylene. Based on the observation of intermediates including allene, vinylacetylene, 1,3-butadiene, 2-butyne, and cyclopentadiene over [Fe]MFI, a reaction network is proposed leading to polyaromatic species. Such reaction intermediates are not observed over the small-pore [Fe]CHA, where ethylene and ethane are the only gas-phase products., (© 2023 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH.)