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Electromechanical components (EMCs) such as relays and contactors have been used extensively in industrial and military areas. The storage reliability of these EMCs has a direct impact on the reliability of the system that contains them. However, during the design phase, it is difficult to predict the storage reliability of EMCs because of few failure rate data of parts, as well as limited testing time and budgets. To address these problems, a virtual Manufacturing and testing method is proposed in this paper, so as to simulate the storage degradation process of batch EMCs. By considering the influence of the quality screening process in the manufacturing process, as well as the unit-to-unit variability of EMCs on the storage degradation paths and the overall life distribution of batch products, the storage failure distribution function is obtained, based on Wiener process. At the same time, the distribution of the diffusion coefficient in the degradation model and the failure distribution model is quantified by introducing testing data of related products as priori information, so as to reflect the uncertainty of the storage degradation process of EMCs. A case study of an electromagnetic relay is carried out to illustrate the effectiveness of the proposed approach.
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Background: Regularly and scientifically participating in athletics is beneficial for physical and mental health. Mood or emotions are important component of psychology and a major indicator of physical and mental health. Positive and negative mood or emotions can have a strong impact on physical responsiveness. The aim of the present study was to explore whether mood or emotional state influence performance in athletics. Methods: Mood, analyzed by Profile of Mood States, and emotional state, reflected by eye movement (looking at times and length), were used to predict track or field performance in training and competition. Results: 1. The profile of track training (except 3rd week) resembled an iceberg profile (highest vigor scores) and the profile on the 3rd week resembled a "melting" iceberg profile, in which positive mood (vigor and self-esteem) was decreased and negative mood, particularly depression and anger, was significantly increased. The profile of field training almost overlapped, with the exception of depression decreasing markedly on the 3rd and 4th weeks. 2. Positive mood overpowered negative mood, particularly following a track competition; positive emotions exceed negative emotions following track and field competition. 3. The results of the regression analysis showed that an improvement in track performance was negatively correlated with a rise in total mood disturbance (TMD), and field performances were positively correlated with positivity of emotion, as tested by eye movement. 4. Good performance in track events appeared to be associated with decreased vigor and increased fatigue during 3rd and 4th track training; decreased depression and fatigue, and increased vigor as well as low observe length of watching negative emotional pictures (NEPs) before track competition. A good performance in field events appeared to be associated with anger decrease and confusion increase, increased fixation counts of watching positive emotional pictures (PEPs), and decreased fixation and observe counts of watching NEPs before field competition. Conclusions: The present study proved that different indicators appeared to measure different sport performances: More indicators of Profile of Mood States inclined to predict track performance, while more eye movement indicators could predict field performance. Mixed methods could provide a better understanding of performance than a single approach alone. These findings provided theoretical support and supplementary data for practical applications in the design of comprehensive training programs.
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This study proposed an extended theory of planned behavior (TPB) to examine the factors that influence pre-service teachers' intention to use technology-enabled learning, using constructivist pedagogical beliefs (CPB) and information and communication technologies (ICT) competencies as antecedent variables for attitudes, subjective norms (SNs), and perceived behavioral control. An online study was conducted with a random sample of pre-service teachers from 7 universities in China, and 811 validated questionnaires were obtained. The results showed that the extended TPB model explained 75% of the variance in intention; attitude, SNs, and perceived behavioral control had a positive and significant effect on intention. Furthermore, SNs had a positive and significant effect on attitude and perceived behavioral control. CPB were the antecedent variables for attitude, SNs, perceived behavioral control, and ICT competencies. ICT competencies were the antecedent variable for SNs and perceived behavioral control. Additionally, through multi-group analysis, this study found significant differences in path relationships between the lower and higher-grade groups. The effect of perceived behavioral control on intention diminished with increased grade level. The effect of SNs on perceived behavioral control reduced. The effect of CPB on attitude and perceived behavioral control on intention diminished. The effect of SNs on attitude increased. This study verified that adding the relationship between antecedent variables of theoretical factors and theoretical factors is an effective way to expand TPB and provided a reference for future studies to focus on the related intention of pre-service teachers. Furthermore, it recommends that Chinese universities should eliminate the hindering influence of CPB, ICT competencies, attitudes, SNs, and perceived behavioral control in the process of preparing pre-service teachers. They should also pay attention to the individual differences of students in different grades and the problems that arise in the existing training.
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BACKGROUND: As the use of diamide insecticides on corn continues to increase, there is growing concern about their residue levels on corn and dietary risks to populations. In this study, the distribution, dispersion and transfer efficiency of two diamide insecticides (tetrachlorantraniliprole (TCAP) and cyantraniliprole (CNAP)) in different parts of corn and soil were investigated in a 1-year field trial in Guangzhou and Lanzhou using two different application methods - spray and drip irrigation, respectively - and the dietary risk of the insecticides to different consumer populations was assessed under the two application methods. RESULTS: The results showed that drip irrigation had a longer persistence period than spraying, and there was a hysteresis in the absorption distribution of the agent in different parts of corn, which was gradually transferred to the leaves after absorption from the roots. The average TE1 (transfer efficiency) and TE2 were 0.230-0.261 and 1.749-1.851 for TCAP and 0.168-0.187 and 2.363-2.815 for CNAP, respectively. At corn harvest, both TCAP and CNAP were below detectable levels in soil and corn. For different consumer populations, hazard quotients ranged from 0.001 to 0.066 for TCAP and from 0.003 to 0.568 for CNAP - both well below 100%. CONCLUSION: This study indicates that TCAP and CNAP applied by spray or drip irrigation are safe for long-term risk of human intake and also provides guidance for the use of both insecticides in agricultural production to control corn pests, especially in arid and semi-arid areas. © 2022 Society of Chemical Industry.
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Inseticidas , Praguicidas , Acetofenonas , Irrigação Agrícola/métodos , Diamida , Humanos , Pirazóis , Medição de Risco , Solo/química , Zea mays , ortoaminobenzoatosRESUMO
In this work, an enzyme-responsive nanovehicle for improving captan (CAP) contact fungicide bioactivity and translocation in plant tissues was synthesized (CAP-MSNs-ß-glucan) by attaching ß-glucan to the outer surface of mesoporous silica nanoparticles. CAP-MSNs-ß-glucan properties were tested by FTIR, ζ-potential, DLS, XRD, TGA, FE-SEM, and HR-TEM. Cargo protection ability of CAP-MSNs-ß-glucan from photolysis and hydrolysis was examined in comparison to CAP commercial formulation (CAP-CF). CAP-MSNs-ß-glucan distribution in plant tissues, bioactivity against Fusarium graminearum, and biotoxicity toward zebrafish (Danio rerio) were tested and compared with that of CAP-CF. CAP-MSNs-ß-glucan results showed good loading efficacy reaching 18.39% and enzymatic-release dependency up to 83.8% of the total cargo after 20 days of ß-glucan unsealing. CAP-MSNs-ß-glucan showed significant release protection under pH changes. MSNs-ß-glucan showed excellent CAP protection from UV. CAP-MSNs-ß-glucan showed better distribution in corn tissues and 1.28 more inhibiting potency to Fusarium graminearum than CAP-CF. CAP-MSNs-ß-glucan showed 1.88 times lower toxicity than CAP-CF to zebrafish after 96 h of treatment. We recommend using such formulations to overcome shortcomings of contact fungicides and achieve better and sustainable farming.
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Understanding the lethal effects of pesticides nano formulations on the targeted organisms (pathogens) and the non-targeted organisms (fish, earthworms, etc) is essential in assessing the probable impact of new technologies on agriculture and environment. Here we evaluated the bioactivity and the biotoxicity of new type of fungicide smart-delivery formulation based on conjugating carboxymethylated-ß-glucans on the mesoporous silica nanoparticles (MSNs) surface after loading chlorothalonil (CHT) fungicide in the MSNs pores. The obtained formulation has been characterized with FE-SEM, and HR-TEM. The CHT loading efficiency has been measured with TGA. The bioactivity of the obtained formulation (CHT@MSNs-ß-glucans) has been tested against four pathogens, fusarium head blight (Fusarium graminearum), sheath rot (Sarocladium oryzae), rice sheath blight (Rhizoctonia solani), and soyabean anthracnose (Colletotrichum truncatum) compared with CHT WP 75% commercial formulation (CHT-WP) and technical CHT. The environmental biotoxicity of CHT@MSNs-ß-glucans compared with CHT-WP has been tested toward earthworm (Eisenia fetida) and zebra fish (Danio rerio). The results showed that CHT@MSNs-ß-glucans has an excellent bioactivity against the subjected pathogens with better inhabiting effects than CHT-WP. CHT@MSNs-ß-glucans toxicity to Eisenia fetida was found 2.25 times lower than CHT-WP toxicity. The LC50 of CHT@MSNs-ß-glucans to zebra fish after the first 24h was 2.93 times higher than CHT-WP. After 96h of treatment, the LC50 of CHT@MSNs-ß-glucans was 2.66 times higher than CHT-WP. This work highlighted the necessity to increase the mandatory bioassays of nano formulations with the major non-target organisms in the environmental risk assessment of new pesticide formulations.
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Fungicidas Industriais , Nanopartículas , beta-Glucanas , Animais , Colletotrichum , Portadores de Fármacos , Fungicidas Industriais/toxicidade , Fusarium , Hypocreales , Nanopartículas/toxicidade , Nitrilas , Porosidade , Rhizoctonia , Dióxido de Silício/toxicidade , beta-Glucanas/toxicidadeRESUMO
In this study, a pesticide controlled release system with dual response characteristics of pH and enzyme triggering was developed. Indoxacarb (IDC) was loaded into hollow mesoporous silica (HMS) nanoparticles, carboxylated ß-cyclodextrin (ß-CD) acted as a capping molecule to couple with the amino-functionalized HMS, and their well-defined morphological structures were confirmed by scanning electron microscopy and transmission electron microscopy. The results showed that the prepared IDC loaded HMS-CD had high loading efficiency (26.42%, w/w) and showed excellent dual response properties to pH and the α-amylase enzyme. IDC loaded HMS-CD nanoparticles showed better insecticidal activity against Spodoptera frugiperda than applying the same dose of IDC emulsifiable concentrate, and the toxicity of IDC loaded HMS-CD to zebrafish was reduced by more than 5-fold, indicating that insecticide delivery systems based on ß-CD-anchored HMS nanoparticles could potentially be applied for sustainable control of pests and reduce harm to non-target organisms and the environment.
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Portadores de Fármacos/química , Inseticidas/farmacologia , Nanopartículas/química , Oxazinas/farmacologia , Dióxido de Silício/química , beta-Ciclodextrinas/química , Animais , Portadores de Fármacos/toxicidade , Nanopartículas/toxicidade , Porosidade , Dióxido de Silício/toxicidade , Spodoptera/efeitos dos fármacos , Peixe-Zebra , beta-Ciclodextrinas/toxicidadeAssuntos
COVID-19 , Saúde Mental , Satisfação Pessoal , Estudantes/psicologia , Adolescente , Adulto , China , Feminino , Seguimentos , Humanos , Masculino , Quarentena/psicologia , Universidades , Adulto JovemRESUMO
Empirical research suggested that individuals with anxiety and/or depression exhibited action on the spur of the moment, with little consideration for the consequences of their actions. However, it remains unclear whether the precise mechanisms underlying the impacts of anxiety and depression on impulsivity. The present study examined how anxiety and depression influence impulsivity, as well as the mediating and moderating role of cognitive flexibility. A sample of 477 Chinese university students was recruited. All participants finished self-report measures of anxiety, depression, impulsivity, and cognitive flexibility. No significant gender difference was found in anxiety, depression, cognitive flexibility, and three subscale scores of impulsivity. Greater scores of anxiety and depression were associated with lower scores of cognitive flexibility and higher levels of impulsivity. Depression and cognitive flexibility could predict attention impulsivity and nonplanning impulsivity, while anxiety and cognitive flexibility could predict motor impulsivity. Cognitive flexibility served as a mediator in the links of anxiety and three subscales of impulsivity. Furthermore, cognitive flexibility moderated the impact of anxiety on motor impulsivity.