Pulse formation mechanisms switching in hybrid mode-locked fiber laser

Hybrid mode-locking has been widely used in enhancing pulse quality, however how the hybrid two mode-locking techniques work remains unclear. In this paper, we experimentally investigate three pulse formation mechanisms in saturable absorbers (SA) and nonlinear polarization evolution (NPE) passively hybrid mode-locked fiber laser, which are SA-dominated, NPE-dominated, and SA-NPE co-domination switching. Clarified the exists dynamic competition and cooperation among the mode-locking techniques. For the first time, the method of simulating filtered gain spectrum with customized filtering is proposed, and the switching of pulse formation mechanisms is numerically investigated using the coupled Ginzburg-Landau equations. Our results deepen the understanding of hybrid mode-locked fiber lasers and provided a foundation for multi-wavelength mode-locked lasers with different mode-locking techniques in a single cavity

The impact of basketball on the social adjustment of Chinese middle school students: the chain mediating role of interpersonal relationships and self-identity

BackgroundThis study examines the effects of 12 weeks of basketball on interpersonal relationships, self-identity and social adjustment of middle school students, as well as exploring the mediating role of interpersonal relationships and self-identity in basketball’s influence on social adjustment.MethodsA total of 87 students from a middle school in Jiangsu Province, China, were selected to participate in this study. A 12-week basketball intervention experiment was conducted, and questionnaires were administered to measure the study variables. Common method bias test, normality test, ANOVA and Pearson correlation analysis were used to analyze the study variables. The theoretical model of this study was also validated using the Process plug-in developed by Hayes, setting p < 0.05 (two-tail) as statistically significant.ResultsAfter a 12-week basketball intervention experiment, the interpersonal relationships, self-identity and social adjustment of the middle school students in the experimental and control groups showed improvement, with the experimental group showing significantly more significant improvement than the control group. A 12-week basketball intervention can positively impact the social adjustment of middle school students, with interpersonal relationships and self-identity acting as a chain mediator in the impact process

Relationship between university students’ physical activity and mobile phone dependence: Mediating effect of subjective well-being and moderating effect of psychological capital

BackgroundWith the ongoing development of the information society, the Internet and smartphones have become an essential way of life, but also fostered the problem of mobile phone dependence. Physical activity and subjective well-being have both been shown to correlate with mobile phone dependence, but the impact of subjective well-being on the relationship between physical activity and mobile phone dependence is not fully understood. This study investigates subjective well-being as a potential mediating variable in the relationship. It also investigates whether psychological capital moderates the association between subjective well-being and mobile phone dependence.MethodsA total of 9,569 students from 38 universities in Jiangsu Province were selected. Participants were surveyed via the online questionnaire distribution platform Questionnaire Star. Common method bias test and Pearson correlation tests were used to analyze the study indicators, and the theoretical model for this study was validated using Process plug-in developed by Hayes and set at p < 0.05 (two- tail) as statistically significant.ResultsThe levels of physical activity, subjective well-being, and psychological capital were all significantly higher for male students than female students. However, female students had a significantly higher level of mobile phone dependence. As predicted, there was a direct negative correlation between physical activity and mobile phone dependence, and subjective well-being mediated that relationship. Psychological capital moderated the relationship between subjective well-being and mobile phone dependence. It also positively moderated the indirect effect between physical activity and mobile phone dependence via subjective well-being

The Effect of Physical Exercise and Internet Use on Youth Subjective Well-Being—The Mediating Role of Life Satisfaction and the Moderating Effect of Social Mentality

Youth subjective well-being is enhanced not only from physical exercise but also from internet use. Based on the 2017 China General Social Survey (CGSS) data, the Bootstrap method was used to examine the mechanisms of the effects of physical exercise and internet use on youth subjective well-being. In this study, the questionnaire data of 619 Chinese young people (18–35 years old) were selected as the sample source. It was found that physical exercise (2.881 ± 1.352) and internet use (4.544 ± 0.756) had positive effects on youth subjective well-being (88.762 ± 11.793). Life satisfaction (2.253 ± 0.826) partially mediated the development of physical exercise and internet use on subjective well-being, with indirect effects of 34.1% and 30.4%, respectively. A social mindset (10.181 ± 1.966) played a moderating role in the relationship between physical exercise and youth subjective well-being and internet use and youth subjective well-being in both groups. The positive effects of physical exercise and internet use on youth subjective well-being gradually increased with the improvement in social mindset. This study revealed the mechanisms of physical activity and internet use on subjective well-being and that life satisfaction and the social mindset of youth are essential factors influencing subjective well-being

The Relationship between Physical Activity and College Students’ Mobile Phone Addiction: The Chain-Based Mediating Role of Psychological Capital and Social Adaptation

The purpose of this study was to investigate the effects and mechanisms of physical activity on mobile phone addiction among college students. A total of 9406 students, ranging from freshmen to seniors, from 35 colleges in four regions of Jiangsu Province were selected using the whole group sampling method. Questionnaires, particularly the International Physical Activity Questionnaire—Long Form (IPAQ), the positive psychological capital scale (PPQ), the social adjustment diagnostic questionnaire (SAFS), and the mobile phone addiction index scale (MPAI), were administered. We found that physical activity negatively predicted mobile phone addiction among university students. Social adaptation partially mediates between physical activity and mobile phone addiction among university students, with separate mediation of psychological capital playing no indirect role. Psychological capital and social adjustment mediate the chain between physical activity and mobile phone dependence among college students. Our findings suggest that physical activity is an important external factor influencing college students’ mobile phone dependence, and it indirectly affects university students’ mobile phone addiction through psychological capital and social adaptation. Improving the physical activity level of college students, enhancing their psychological capital, and promoting improved social adaptation are important ways to prevent mobile phone addiction among college students

Effects of aerobic exercise on body self-esteem among Chinese college students: A meta-analysis.

ObjectiveTo investigate the effect of aerobic exercise on five dimensions of physical self-worth, exercise capacity, physical condition, physical attractiveness, and physical quality in body self-esteem of Chinese college students.MethodsBy searching PubMed, Web of Science, Cochrane Library, CNIK database, VIP database, WANFANG database platform, we searched for the subject terms or keywords "body self-esteem", "Chinese college students", "Systematic evaluation", "Aerobic exercise", "Exercise intervention", "Meta-Analysis". The search method was a combination of subject terms and keywords and title, and the search period was from database creation to The search was conducted from database creation to May 2022. A total of 3221 articles were searched, and 9 articles were included in the study through repeated screening. Risk of bias was assessed with Cochrane and the quality of studies in the literature was assessed using Grade pro software. The outcome indicators of the included literature were analysed using review manager 5.4 software and StataMP 17.0 software.ResultsNine papers including 1613 subjects were included. results of Meta-analysis showed that aerobic exercise was effective in improving physical self-worth (WMD = 1.46, 95% CI: 1.08-1.83, pConclusionAerobic exercise can effectively improve the body self-esteem of Chinese college students. In exercise, male students pursue is athletic ability and physical fitness, and female students pursue is the sense of physical self-worth and physical attractiveness. Aerobic exercise has a greater increase in body self-esteem for obese or Obese college students. Aerobics and physical dance are the most cost-effective for improving body self-esteem. Medium-intensity relative to low-intensity exercise was effective for body self-esteem intervention. A single exercise session of 90 minutes was more effective than a single 30-minute session in boosting body self-esteem, and the overall intervention duration of 16 weeks was more effective than 10 weeks

Monolithic Saturable Absorber with Gallium Arsenide Nanowires Integrated on the Flexible Substrate for Optical Pulse Generation

In this work, we demonstrated a kind of flexibly monolithic saturable absorber (SA) with GaAs nanowires (NWs) on polyimide (PI) plastic substrate for broadband optical modulation at 1.0 and 1.5 µm, separately. The monolithic SA sample was prepared by the metalorganic vapor phase epitaxy (MOVPE) method. The crystal structure and element analysis were examined carefully by high-resolution scanning transmission electron microscopy (HRSTEM) and energy-dispersive X-ray spectroscopy (EDX). We observed a high-density distribution of NWs on the flexible substrate by scanning electron microscopy (SEM). In addition, linear and nonlinear optical properties of the sample were examined by testing the photoluminescence and absorption properties, which showed its potential application as an optical switch due to the pure semiconducting properties. After the characterizations, we experimentally demonstrated this monolithic SA for laser modulation at 1.0 and 1.5 µm, which yielded the minimum optical pulse widths of 1.531 and 6.232 µs, respectively. Our work demonstrated such a kind of monolithic flexible NW substrate-integrated device used for broadband optical modulation, which not only eased the integration process of NWs onto the fiber endface, but also proved the potential of easily integrating with more semiconducting nanomaterials (e.g., graphene, MoS2, …) to realize monolithic active flexible photonic systems, such as a microscale phase modulator, delay-line, and so on, paving an easy avenue for the development of both active and flexible photonic devices