Prior studies report that the business group structure and the associated intra-group capital flows are prone to conflicts of interest between controlling shareholders and minority investors. Yet business group is a prevalent and stable structure around the globe, particularly where capital markets are underdeveloped. Using data from China, this paper empirically studies the trade-off between the negative and positive roles played by intra-group capital flows and tests the efficiency implications of such trade-off. We find that from the perspective of the (...) whole group, intra-group capital flows are most efficient when the groups are least subject to conflicts of interest between controlling shareholders and minority shareholders and when they face strong external financing constraints. (shrink)

The unprecedented economic changes taking place in China over the past three decades have led to significant new fiscal pressures for the central and provincial governments. The relative decline of public ownership and rise of the private sector has forced governments to substitute revenues from new taxes for the funds formerly provided by public enterprises. The shift from profit distribution to tax revenues has led to a realignment of power between local governments and the central government while the growing disparity (...) in wealth between have and have-not provinces has increased the pressure on the central government to further consolidate control over tax revenues and to apply the enhanced revenues to fund fiscal redistribution transfers. At the same time, modernization of the economy and the influx of foreign investment have created pressure to revamp tax laws and tax administration so both resemble more closely western market economy norms. These processes may lead to an irreversible shift of fiscal power from provincial governments to the central government and a consequent consolidation of political power, changing forever the political economy of modern China. (shrink)

Background: Social, emotional, and behavioral problems in childhood are key predictors of persistent problem behaviors throughout the life courses of individuals. Early parental intervention training, as an important preventive measure, plays a critical role in improving the social, emotional, and behavioral development of children.Method: We conducted a systematic review and meta-analysis to analyze the intervention effects of the latest literature on Triple P, which is a multilevel system that provides treatment and prevention for children at risk of social, emotional, and (...) behavioral problems via parenting approaches to enhance the parenting knowledge, skills, and confidence of parents. Since the literature on Triple P from 1970 to 2012 has already been systematically reviewed, this study searched the literature from 2013 to 2020 from the Web of Science, EBSCO, ERIC, MEDLINE, CNKI, and Triple P Evidence-Base website using multiple search strategies. This study differs from the existing research by its inclusion criteria of studies that use experimental designs or quasi-experimental designs. A total of 37 studies were included in the final analysis, and STATA 16.0 was used for evaluation while RevMan 5.3 for risk of bias assessment.Results: The results show that Triple P can promote the social competence of children and prevent their emotional and behavioral problems to a certain extent. Simultaneously, the proximal effects on parents mainly included changing negative parenting styles, reducing parenting conflicts, and improving parenting efficacy and self-confidence. The distal effects on parents included reducing the psychological adjustment problems of parents, improving parent–child relationships, and reducing parent–child conflict. However, the meta-analysis results did not show a significant effect of Triple P on improving the marital relationship quality and satisfaction of parents. Components of the program intervention, including intervention level, service delivery format, service method, and program implementation setting, and the age of the children were crucial moderating factors on the outcomes of Triple P.Conclusion: This study systematically reviewed the latest Triple P intervention literature and found the significant effectiveness of Triple P on the SEB problems of children and parenting outcomes and the moderators of the effect size. (shrink)

Previous studies have examined the outcome evaluation related to the self and other, and recent research has explored the outcome evaluation of the self and other with pro-social implications. However, the evaluation processing of outcomes in the group in need remains unclear. This study has examined the neural mechanisms of evaluative processing by gambling for the self and charity, respectively. At the behavioral level, when participants make decisions for themselves, they made riskier decisions following the gain than loss in small (...) outcomes and engage in more risky behaviors following the loss than gain in large outcomes. However, magnitude and valence did not affect the next risky behavior when participants made decisions for the charity. At the neurophysiological level, the results found that the FRN was larger for the charity outcome than for the self-outcome. For FRN, the valence difference of small outcomes was smaller than that of large outcomes. The P3 response was larger for the self-outcome than for the charity outcome. Meanwhile, compared with the small outcome, the self-charity discrepancies have a significant difference in large outcomes. In addition, the FRN amplitude for self in large outcomes was negatively correlated with the upcoming risky choices, regardless of outcome valence. The behavioral results suggest that people are more likely to optimize strategies for themselves than for the charity. The ERP findings indicated that people focus more on charity outcome than self-outcome in the early stage. In the middle and late stages, people turn attention to their outcomes, and the difference between self’s and charity’s outcome varies with the magnitude. Specifically, it is only in large outcomes that people engage more emotional attention or motivation in their outcomes, but self and charity outcomes had a similar emotional engagement in small outcomes. (shrink)

The coronavirus disease 2019 continues to spread globally. This infectious disease affects people not only physically but also psychologically. Therefore, an effective psychological intervention program needs to be developed to improve the psychological condition of patients screened for fever during this period. This study aimed to investigate the effect of a brief mindfulness intervention on patients with suspected fever in a screening isolation ward awaiting results of the COVID-19 test. The Faces Scale and the Emotional Thermometer Tool were used to (...) investigate 51 patients who were randomly divided into an intervention group and a control group. All patients completed self-rating questionnaires online at the time they entered the isolation ward and before they were informed of the results. The intervention group listened to the mindfulness audios through hospital broadcasts in the isolation ward before their lunch break and while they slept. Compared with the control group, the intervention group’s life satisfaction score increased and the emotional thermometer score decreased. The anxiety scores and the needing help scores decreased significantly. Distress, depression, and anger also decreased, but did not reach significance. Brief mindfulness interventions can alleviate negative emotions and improve the life satisfaction of patients in the isolation ward who were screened for COVID-19 during the waiting period. (shrink)

IntroductionNew nurses struggled with time management, which was a prominent theme in safety care for patients. However, the transition training of time management for new nurses was complicated and ignored by clinical managers. The purpose of this study was to understand the level of new nurses’ TMD from a nationwide perspective and detect the influencing factors of the TMD.Materials and methodsA cross-sectional study design with a stratified sampling method was sampled in China. Six hundred and seventy new nurses within the (...) first year of employment were recruited. New nurses’ time management disposition, job stressors, self-efficacy, clinical communication competence, and safety behavior were measured by corresponding scales.ResultsNew nurses showed the best sense of time’s value, followed by the sense of time efficacy and time monitoring view for time management disposition. The related factors of time management disposition were communication skills, safety behavior, job stressors, and being without a preceptor. New nurses’ time management disposition was at a moderate level and they performed worse in time allocation. The highest education, with or without a preceptor, the experience of part-time jobs, and class cadre were significantly influencing the time management disposition of new nurses.ConclusionNursing managers should pay attention to new nurses’ time management disposition. Reducing the job stressors, improving communication ability, and safe behavior were important measures to improve the time management disposition. (shrink)

A neural network is a model of the brain’s cognitive process, with a highly interconnected multiprocessor architecture. The neural network has incredible potential, in the view of these artificial neural networks inherently having good learning capabilities and the ability to learn different input features. Based on this, this paper proposes a new chaotic neuron model and a new chaotic neural network model. It includes a linear matrix, a sine function, and a chaotic neural network composed of three chaotic neurons. One (...) of the chaotic neurons is affected by the sine function. The network has rich chaotic dynamics and can produce multiscroll hidden chaotic attractors. This paper studied its dynamic behaviors, including bifurcation behavior, Lyapunov exponent, Poincaré surface of section, and basins of attraction. In the process of analyzing the bifurcation and the basins of attraction, it was found that the network demonstrated hidden bifurcation phenomena, and the relevant properties of the basins of attraction were obtained. Thereafter, a chaotic neural network was implemented by using FPGA, and the experiment proved that the theoretical analysis results and FPGA implementation were consistent with each other. Finally, an energy function was constructed to optimize the calculation based on the CNN in order to provide a new approach to solve the TSP problem. (shrink)

In light of the dramatic growth of Chinese learners worldwide and a need for cross-linguistic research on Chinese literacy development, this study drew upon theories of visual complexity effect (Su & Samuels, 2010) and dual-coding processing (Sadoski & Paivio, 2013) and investigated a) the effects of character properties (i.e., visual complexity and radical presence) on character acquisition and b) the relationship between individual learner differences in radical awareness and character acquisition. Participants included adolescent English-speaking beginning learners of Chinese in the (...) U.S. Following Kuo et al. (2014), a novel character acquisition task was used to investigate the process of acquiring the meaning of new characters. Results showed that a) characters with radicals and with less visual complexity were easier to acquire than characters without radicals and with greater visual complexity; and b) individual differences in radical awareness were associated with the acquisition of all types of characters, but the association was more pronounced with the acquisition of characters with radicals. Theoretical and practical implications of the findings were discussed. (shrink)

1, Kong Zi and Laozi believed that a philosophy, the thing transformation, under certain must the condition, can complete. If does not have this kind of condition, you insist to do, is impossible to succeed. They thought that the human society the highest ideal is: Everybody can be the social work selflessly, has the common rich life. But must be, society's productive forces may meet all person's need, moreover also has unnecessary. But, Kong Zi's society, the productive forces is very (...) low, therefore Kong Zi sighs, he has the ideal, but is unable to achieve. laozi believed that broad ideal, if does not meet the time requirement, is unable to achieve. Therefore lives in seclusion. 2, the sakya-muni spirit, is higher than Kong Zi and Laozi. It saw that lives of the people in sea of bitterness. It wants the universal salvation people, is separated from sea of bitterness, arrives at the happy other shore. Therefore, it gives up king's life, enters sea of bitterness, with the misery common people, lives together, struggles together. (shrink)

Previous studies have demonstrated that orientation-specific deprivation in early life can lead to neural deficits of spatial vision in certain space, and can even result in meridional amblyopia. Individuals with astigmatism are the optimal and natural models for exploring this asymmetric development of spatial vision in the human visual system. This study aims to assess the contrast sensitivity function and EEG signals along two principal meridians in participants with regular astigmatism when being optimal optical corrected. Twelve participants with astigmatism and (...) thirteen participants with were recruited in the current study. CSFs and spatial sweep visual evoked potentials were measured with vertical and horizontal sinewave gratings along two principal meridians monocularly. Area under log CSF, spatial frequency threshold corresponding to 80% contrast gratings, and CSF acuity were calculated from CSF test. In addition, sVEP amplitudes and thresholds were calculated with the recursive least square method. Participants with astigmatism exhibited marked vertical-horizontal resolution disparities even after they were corrected with optimal optical corrections. CSF tests showed that AULCSF along weak meridian was lower than that along strong meridian in both groups. Significant meridional disparity of CSF acuity was also found in both groups. In addition, the MA group showed larger meridional disparity compared to the AST group. Spatial sVEP thresholds also supported the existence of marked meridional disparity. Our results suggest that meridian-specific partial deprivation in early life might lead to monocularly asymmetric development of spatial vision in the human visual system. In terms of application, we tested the feasibility and reliability of adopting psychophysical and EEG scalings to investigate the asymmetric development of spatial vision related to astigmatism. These paradigms are potentially applicable to reduce and even eliminate the meridional disparity in the primary visual cortex by adopting perceptual learning or other vision-related interventions. (shrink)

As it has become more and more urgent to solve the problems of environmental protection, we consider it necessary to conduct multilevel studies to examine the impact of business strategy on both employees’ and firms’ performances in environmental protection. Synthesizing the perspectives of strategic orientation, corporate strategy, and firm performance, we propose a comprehensive theoretical model linking market orientation and environmental performance. Based on a survey of 134 matched chief executive officers, senior marketing managers and frontline workers from Chinese firms, (...) we found that market orientation positively affects environmental strategy which, in turn, influences both environmental product quality and employees’ environmental involvement. These latter two variables consequently have a positive influence on environmental performance. At the same time, environmental commitment moderates the link between market orientation and environmental strategy. (shrink)

Although some cognitive studies provided reasons that children with low socioeconomic status (SES) showed poor mathematical achievements, there was no explicit evidence to directly explain the root of lagged performance in children with low SES. Therefore, the present study explored the differences in neural correlates in the process of symbolic magnitude comparison between children with different SES by the event-related potentials (ERP). A total of 16 second graders from low SES families and 16 from middle/high SES families participated in this (...) study. According to the results of anterior N1 (early attention) and P2 (extraction of numerical meaning) over frontal region, the differences among children with different SES were manifested as differences in general neural activities in terms of attention and top-down cognitive control. In the late stage of cognitive processing, there was no significant difference in the average amplitude of the LPC between the children with different SES, indicating that low SES did not influence the information encoding and memory updating of numerical representation responsible by the parietal lobe. The educational implications of this study were mentioned in the discussion. (shrink)

The Depression Anxiety Stress Scale-21 is an instrument in the assessment of mental health status. The current study recruited 1,532 Chinese hospital workers [74.4% female; mean age = 31.97 years] to examine the reliability, latent structure, and measurement invariance of the DASS-21 between genders. The Cronbach’s α values were greater than 0.90 for total score. This study examined four possible models of the DASS-21 using the confirmatory factor analysis in Chinese hospital workers. The results from CFA revealed that the latent (...) structure of the DASS-21 in medical staffs is best represented by a one-factor model. Then we used the one-factor model to examine measurement invariance across genders by using a multiple-group categorical CFA. All values of root mean square error approximation were less than 0.08, all Comparative Fix Index and Tucker–Lewis Index values were greater than 0.90, all ΔCFI values were less than 0.010, and ΔRMSEA were less than 0.015. These findings supported the gender invariance of the DASS-21 among Chinese hospital workers. (shrink)

ABSTRACTCognitive control enables us to adjust behaviours according to task demands, and emotion influences the cognitive control. We examined how task-irrelevant emotional stimuli impact the ability to inhibit a prepared response and then programme another appropriate response. In the study, either a single target or two sequential targets appeared after emotional face images. Subjects were required to freely viewed the emotional faces and make a saccade quickly upon target onset, but inhibit their initial saccades and redirect gaze to the second (...) target if it appeared. We found that subjects were less successful at inhibiting their initial saccades as the inter-target delay increased. Emotional faces further reduced their inhibition ability with a longer delay, but not with a shorter delay. When subjects failed to inhibit the initial saccade, the longer delay produced longer intersaccadic interval. Especially, positive faces lengthened the intersaccadic interval with a l... (shrink)

Memristor is the fourth basic electronic element discovered in addition to resistor, capacitor, and inductor. It is a nonlinear gadget with memory features which can be used for realizing chaotic, memory, neural network, and other similar circuits and systems. In this paper, a novel memristor-based fractional-order chaotic system is presented, and this chaotic system is taken as an example to analyze its dynamic characteristics. First, we used Adomian algorithm to solve the proposed fractional-order chaotic system and yield a chaotic phase (...) diagram. Then, we examined the Lyapunov exponent spectrum, bifurcation, SE complexity, and basin of attraction of this system. We used the resulting Lyapunov exponent to describe the state of the basin of attraction of this fractional-order chaotic system. As the local minimum point of Lyapunov exponential function is the stable point in phase space, when this stable point in phase space comes into the lowest region of the basin of attraction, the solution of the chaotic system is yielded. In the analysis, we yielded the solution of the system equation with the same method used to solve the local minimum of Lyapunov exponential function. Our system analysis also revealed the multistability of this system. (shrink)

Objective wealth plays an important role in social interaction and economic decision making. Previous studies indicate that objective wealth of others may influence the way we participate in resources allocation. However, the effect of objective wealth on responses to fairness-related resource distribution is far from clear, as are the underlying neural processes. To address this issue, we dynamically manipulated proposers’ objective wealth and analyzed participants’ behavior as responders in a modified Ultimatum Game, during which event-related potentials were recorded. Behavioral results (...) showed that participants were prone to reject unfair proposals although that rejection would reduce their own benefit. Importantly, participants were more likely to accept unfair offers from proposers with low objective wealth than from proposers with high objective wealth, with a drastic increase in acceptance rates of unfair offers from 32.79 to 50.59%. Further electrophysiological results showed that there was significantly enhanced feedback-related negativity amplitude toward proposers with high objective wealth for unfair offers. Furthermore, the late frontal negativity amplitude was larger for all the conditions which are not high-fair, which might be the only option that did not elicit any ambiguity. These findings suggest a strong role of proposers’ objective wealth in modulating responders’ behavioral and neural responses to fairness. (shrink)

Objective: To systematically analyze the effectiveness of technology-based interventions for reducing loneliness in older adults.Methods: We searched relevant electronic databases from inception to April 2021, which included Cochrane Library, PubMed, Web of Science, SpringerLink, EMBASE, CNKI, and Wanfang. The following criteria were used: study design—randomized controlled trial designs, people—older adults, intervention—technology-based interventions in which a core component involved the use of technology to reduce loneliness in older adults; and outcome—reduction of loneliness level in terms of rating scale scores. Two reviewers (...) independently identified eligible studies, extracted data, and assessed the risk of bias in the included studies. A third reviewer resolved any conflicts. The Cochrane Collaboration's bias assessment tool was used to evaluate the risk of bias for the included studies, and Review Manager 5.4 software was used for the meta-analysis. A random effects model was adopted to measure estimates of loneliness reduction, and standard mean differences with a 95% confidence interval were calculated for each intervention-control contrast, and the I2 statistic was applied to examine heterogeneity.Results: A total of 391 participants from six RCTs were included in the review. Of these, three studies were rated as low-quality, and the remaining three were rated as moderate-quality studies. The meta-analysis showed that the evidence regarding the effects on loneliness of technology-based interventions compared with control groups was uncertain, and suggested that technology-based interventions resulted in little to no difference in loneliness reduction compared to control groups. Two types of technology-based interventions were identified: smartphone-based video calls and computer-based training with Internet usage. The subgroup analysis found low-quality evidence to support the effectiveness of both intervention types.Conclusions: We found no current evidence to support that technology-based interventions were effective compared to different control conditions in reducing loneliness in older adults. This suggests that more research is needed to investigate the effects of technology-based interventions on loneliness in older adults. (shrink)

The coronavirus disease 2019 pandemic has severely damaged the global industrial supply chain and accelerated the digital transformation of the global economy. In such rapidly changing environments, multinational corporations should encourage employees to be more innovative in various fields than ever before. With the onset of the COVID-19 pandemic, employees have become psychologically anxious, their working conditions have deteriorated, and they are in danger of losing their jobs. In this study, we aim to address the question of whether servant leadership (...) facilitates the innovative behavior of employees working in emerging-market MNCs when servant leadership is adopted within the firms. In addition, we explore the mediating roles of work–life balance and psychological stability perceived by employees, and the moderating role of organizational climate in the relationship between servant leadership and MNC employees' innovative behavior. In doing so, we collected data from a sample of 307 Chinese employees who are employed by five different Chinese MNCs from the Internet, information technology, electronics, and e-commerce industries. Based on a sample of survey data collected from employees of Chinese MNCs, we empirically test these ideas by specifically examining how servant leadership may shape the innovation behavior of employees in these MNCs. The results suggest that servant leadership positively influences employees' innovative behavior, and that the contribution of servant leadership to employees' innovative behavior is mediated by work–life balance and psychological stability as well as moderated by the degree of organizational climate. Moreover, the different organizational climates of these MNC employees are also expected to significantly shape the relationship between servant leadership and employees' innovative behavior. This study enriches our understanding of the importance of servant leadership in driving the innovative behaviors of employees in emerging-market MNCs and provides new insights into the mechanisms through which emerging-market MNCs can motivate their employees to be more innovative in their jobs. Thus, this study contributes to the research on human resource management by offering important implications vis-à-vis how MNCs manage their employees more effectively in addressing and responding to the dramatically changing global landscape in the post COVID-19 era. (shrink)

Noninvasive brain stimulation provides a promising approach for the treatment of neuropsychiatric conditions. Despite the increasing research on the facilitatory effects of this kind of stimulation on the cognitive processes, the majority of the studies have used the standard stimulation approaches such as the transcranial direct current stimulation and the conventional repetitive transcranial magnetic stimulation which seem to be limited in robustness and the duration of the transient effects. However, a recent specialized type of rTMS, theta-burst stimulation, patterned to mimic (...) the natural cross-frequency coupling of the human brain, may induce robust and longer-lasting effects on cortical activity. Here, we aimed to investigate the effects of the intermittent TBS, a facilitatory form of TBS, over the right DLPFC, a brain area implicated in higher-order cognitive processes, on visuospatial working memory performance. Therefore, iTBS was applied over either the rDLPFC or the vertex of 24 healthy participants, in two separate sessions. We assessed VSWM performance using 2-back and 4-back visuospatial tasks before iTBS, and after the iTBS. Our results indicate that the iTBS over the rDLPFC significantly enhanced VSWM performance in the 2-back task, as measured by the discriminability index and the reaction time. However, the 4-back task performance was not significantly modulated by iTBS. These findings demonstrate that the rDLPFC plays a critical role in VSWM and that iTBS is a safe and effective approach for investigating the causal role of the specific brain areas. (shrink)

Given that women CEOs are usually more risk averse, engage less in opportunistic behavior, and provide higher quality earnings than men CEOs, we argue that firms with women CEOs are likely to face lower operational and information risk and thus enjoy cheaper external funds. Using a large sample of Chinese A-share listed firms operating from 2006 to 2012, we find consistent evidence that Chinese banks tend to impose lower loan costs on firms with women CEOs compared to firms with men (...) CEOs. This effect is more pronounced for non-state-owned enterprises than for state-owned enterprises, for firms without political connections than for firms with political connections, and during non-crisis periods. We do not find any significant effects for firms with women chairpersons, CFOs, or directors. (shrink)

Based on the job demands-resources model, this study explored the relationships of work engagement, job performance and psychological capital in industry employees. A total of 399 IT programmers were recruited and completed the work engagement scale, knowledge employee job performance scale and psychological capital questionnaire. The results showed that: There is a relationship between work engagement and job performance, which may not be linear but inverted U-shaped, and psychological capital plays a moderating role in the inverted U-shaped relationship between work (...) engagement and job performance. (shrink)

PurposeThe purpose of this study was to introduce an orthogonal experimental design to improve the efficiency of building and optimizing models for freezing of gait prediction.MethodsA random forest model was developed to predict FOG by using acceleration signals and angular velocity signals to recognize possible precursor signs of FOG. An OED was introduced to optimize the feature extraction parameters.ResultsThe main effects and interaction among the feature extraction hyperparameters were analyzed. The false-positive rate, hit rate, and mean prediction time were 27%, (...) 68%, and 2.99 s, respectively.ConclusionThe OED was an effective method for analyzing the main effects and interactions among the feature extraction parameters. It was also beneficial for optimizing the feature extraction parameters of the FOG prediction model. (shrink)

This study aimed to investigate mothers’ parenting stress and explore its relationship with associated demographic variables in two-child families involving preschool children. A sample of 621 two-child families and a comparison group of 319 one-child families from China participated in the study; the children were aged between 3 and 7. The results showed that mothers of two-child families had higher parenting stress than those of one-child families; within the two-child families, demographic variables, such as birth order, gender combination, and the (...) age gap were found to have significant effects on maternal stress levels; and in two-child families, families with an income of less than 3000 yuan had significantly higher maternal stress than families with an income of more than 6000 yuan. (shrink)

Through the recognition of ocean sediment sonar images, the texture in the image can be classified, which provides an important basis for the classification of ocean sediment. Aiming at the problems of low efficiency, waste of human resources, and low accuracy in the traditional manual side-scan sonar image discrimination, this paper studies the application of image recognition technology in sonar image substrate texture discrimination, which is popular in many fields. At the same time, considering the scale complexity, diversity, multisources, and (...) small sample characteristics of the marine sediment sonar image texture, the transfer learning is introduced into the image recognition, and the K-means clustering algorithm is used to reset the prior frame parameters to improve the speed and accuracy of image recognition. Through the experimental comparison between the original model and the new model based on transfer learning, the AP value of the yolov3 model based on transfer learning can reach 84.39%, which is 0.97% higher than that of the original model, with considerable accuracy and room for improvement; it takes less than 0.2 seconds. This shows the applicability and development of image recognition technology in texture discrimination of bottom sonar images. (shrink)

Contemporary social reform promotes rapid social transformation, and social practice has a special educational function in higher education. However, research shows weak willingness to participate in social practice among college students. Using the mixed research method, 438 completed questionnaire surveys on perceived environmental support were collected from college students. The influence of perceived environmental support on Chinese college students’ willingness to participate in social practice was analyzed using partial least squares structural equation modeling, and an empirical test was conducted. The (...) findings are as follows: Perceived environmental support significantly impacts students’ participation attitude and perceived behavioral control. Participation attitude and perceived behavioral control significantly influence participation intention, but behavioral norms have no significant influence. Participation intention and perceived behavioral control significantly influence actual behavior. This study provides the theoretical basis of perceived environmental support for future research on social practice participation intention and offers some theoretical guidance for the implementation of social practice in China. (shrink)

Coronavirus disease cases and COVID-19-related deaths have been increasing worldwide since the outbreak in 2019. Before the mass vaccination campaign for COVID-19, the main methods for COVID-19 control in China were mass testing and quarantine. Based on the transmission mechanism of COVID-19, we constructed a dynamic model for COVID-19 transmission in two typical regions: Beijing and Xinjiang. We calculated the basic reproduction number R 0, proved the global stability of COVID-19 transmission via the Lyapunov function technique, and introduced the final (...) size. We assessed the effectiveness of mass testing and quarantine. Sensitivity analysis indicated that the more the people were tested per day, the larger is the quarantine proportionality coefficient, the earlier the source location was determined, and the better is the controlling effect. In addition, it was more effective to increase the coefficient of quarantine if the population density in the region was low. To eliminate the pandemic, the government has to expand testing and quarantine, requiring a large amount of continuous manpower, material, and financial resources. Therefore, new control measures should be developed. (shrink)

This paper presents a numerical investigation of bird attitude angles affecting the soft-impact damage of a full fan assembly. Firstly, considering the geometry of a mallard, a real bird model is established by the Smoothed Particle Hydrodynamics method and calibrated with available test data. Then, complying with airworthiness requirements, simulations of a full-bladed fan assembly subjected to a real bird were conducted to determine the critical ingestion parameters. Furthermore, a real bird with different attitude angles aimed at a full fan (...) assembly was simulated. Results show that attitude angles of the bird produce a significant impact on the effect of the bird strike on rotating blades and would increase the possibility of blade failures, especially for the yaw angle of -45° and the pitch angle of −60°. It is invaluable for commercial airlines and engine manufactures to provide safe flight and landing by adopting the real bird model with critical yaw and pitch angles in the design for resistance to bird ingestion. (shrink)