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Purpose: This study was to estimate the impact of COVID-19 on sedentary behavior for Chinese university students during the pandemic period, as well as explore how sedentary behavior changed as a function of gender. Methods: We conducted an online questionnaire (the Sedentary Behavior Questionnaire) on 1487 (947 males & 513 females; Age 19.72± 1.32yr., BMI = 21.12 ± 4.50) students from one university in China during the pandemic period and students retrospectively recalled pre-pandemic physical activity levels (March 29- April 15, 2020). Sedentary behavior was measured using the short version of the Sedentary Behavior Questionnaire (SBQ). Sedentary behavior of social isolation in a typical week during the COVID-19 pandemic period and before the COVID-19 pandemic were measured based on SBQ. The data were analyzed using a paired-samples t-test. Chi-square tests were to compare categorical variables. Results: Before the COVID-19, on weekdays, survey participants averaged engaged in 11.41 (SD =3.93) hours of SB, 10.97 (SD = 3.85) hours of SB in males, 12.25 (SD =3.94) hours of SB in females; on weekends, survey participants averaged engaged in 13.18 (SD =4.06) hours of SB, 12.74 (SD = 3.96) hours of SB in males, 14.04 (SD =4.11) hours of SB in females. During the COVID-19, on weekdays, survey participants averaged engaged in 13.34 (SD =3.78) hours of SB, 12.90 (SD = 3.67) hours of SB in males, 14.19 (SD =3.83) hours of SB in females; on weekends, survey participants averaged engaged in 14.48 (SD =3.93) hours of SB, 14.10 (SD = 3.81) hours of SB in males, 15.22 (SD =4.04) hours of SB in females. Overall, on weekdays, COVID-19 on average appeared to increase SB by 1.93 (16.91%↑, 95% CI = 1.74, 2.12) hours, an increase in daily total SB by 1.92 (17.50%↑, 95% CI = 1.92, 2.15) hours for males, and an increase 1.94 (15.84%↑, 95% CI = 1.62, 2.27) hours in females. On weekends, COVID-19 on average appeared to increase SB by 1.30 (9.86%↑, 95% CI = 1.12, 1.48) hours, an increase in daily total SB by 1.36 (10.68%↑, 95% CI = 1.13, 1.58) hours for males, and an increase 1.18 (8.40%↑, 95% CI = 0.87, 1.50) hours in females. Conclusions: The COVID-19 led to an increase in sedentary behavior of Chinese university students. The total sedentary time of female students per week was higher than that of male students. Public policy action might be urgently needed to decrease the sedentary behavior of Chinese university students.

The global demand for mineral resources has led to the gradual transformation of the mining industry from the traditional shallow, small-scale mining mode to the high-intensity mining of deep underground mines. Due to the high stress, high temperature, high permeability, and easy disturbance of deep mines, new challenges have been brought to the mining of materials. Some scholars have improved the thermal insulation performance of concrete by adding low thermal conductivity materials such as ceramsite, shell, and natural fiber to traditional shotcrete, but there are still high costs, insufficient support strength, and unsatisfactory thermal insulation effects. Given the background related to the fact that it is still not possible to fully recycle the large amount of solid waste generated by mining activities, this paper, with traditional shotcrete as its basis, uses coal fly ash to replace part of the cement and tailings to replace part of the sand and gravel aggregate. In addition, it adds basalt fiber to reduce thermal conductivity and restore strength. An orthogonal experiment of three factors and three levels was designed to explore a new type of solid waste-based thermal insulation support shotcrete material. Through the testing and analysis of the mechanical and thermal properties of the specimens, it was concluded that the optimal ratio of the materials was 45% fly ash, 50% tailings, and 25% basalt fiber (the percentage of the total mass of fly ash and cement). The compressive strength of the specimens after curing for 28 days could reach 16.26 MPa, and the thermal conductivity and apparent density were 0.228561 W/(m·k) and 1544.00 kg/m3, respectively. By using COMSOL Multiphysics multi-physics coupling software to analyze the coupling of the stress field and temperature field, it was concluded that the optimum thickness of the thermal insulation layer of this material was 150 mm. The field application in a mine in Shandong Province proved that it met the effects of thermal insulation (the ability to isolate heat conduction) and support. The successful trial of this material provides a new idea for the solving of the problem of heat damage and solid waste utilization in deep mines, which has a certain practical significance.

Long-term monocultures of tea and the excessive use of chemical fertilizer lead to the degradation of soil quality. Improving the soil quality of ex-tea plantations through vegetation restoration is an important task. However, the changes in soil nutrients, fungal communities, and the effects of microorganisms on soil nutrients after reforestation remain unclear. Therefore, in this study, we aimed to explore the effects of Pinus and Chinese fir on soil nutrients and fungal communities in ex-tea plantation areas that were subjected to the reforestation modes of pure forest and mixed forest by measuring soil chemical properties and ITS rRNA gene sequences. The results showed that (1) after reforestation, the relative normalized difference vegetation index (NDVI) of the Mixed forest, Mixed Pine and Mixed Fir areas increased (p < 0.05) compared to that of pure forest; (2) the soil organic carbon (SOC), total nitrogen (TN), and N:P ratios of the mixed forest increased by an average of 54%, 90%, and 299% (p < 0.05) compared to pure forest, whereas the total phosphorus (TP) and available potassium (AK) decreased by an average of 39% and 89% (p < 0.05); and (3) there was no significant difference in the diversity of the fungal communities of the pure and mixed forests, but the fungal phyla Mucoromycota, Glomeromycota, and Rozellomycota were significantly different in the pure and mixed forests. This differing microbial composition led to a significant increase (p < 0.05) in symbiotrophs (ecotomycorhizal, ericoid mycorhizal) in the mixed forest, which was negatively correlated with the soil TP and positively correlated with the TN and the N:P ratio. In addition, there was also a significant decrease (p < 0.05) in complex nutrient types (ectomycorrhizal-fungal parasite-plant saprotroph-wood saprotroph), which were negatively correlated with the SOC and TN, and arbuscular mycorrhizas, which were positively correlated with the TP. Our results show that the chemical properties of soils and the structure of the fungal communities changed significantly due to the reforestation of Chinese fir and Pinus, and the mixed forest mode of reforestation was more conducive to improving the soil quality; therefore, a mixed forest of Chinese fir and Pinus can be used to improve degraded soils in ex-tea planting areas.

This article examines the early modern household's importance for producing experimental knowledge through an examination of the Halifax household of Margery and Henry Power. While Henry Power has been studied as a natural philosopher within the male-dominated intellectual circles of Cambridge and London, the epistemic labour of his wife, Margery Power, has hitherto been overlooked. From the 1650s, this couple worked in tandem to enhance their understanding of the vegetable world through various paper technologies, from books, paper slips and recipe notebooks to Margery's drawing album and Henry's published Experimental Philosophy. Focusing on Margery's practice of hand-colouring flower books, her copied and original drawings of flowers and her experimental production of ink, we argue that Margery's sensibility towards colour was crucial to Henry's microscopic observations of plants. Even if Margery's sophisticated knowledge of plants never left the household, we argue that her contribution was nevertheless crucial to the observation and representation of plants within the community of experimental philosophy. In this way, our article highlights the importance of female artists within the history of scientific observation, the use of books and paperwork in the botanical disciplines, and the relationship between household science and experimental philosophy.

The assessment of the use of cooking oil/fat and salt in dining food is an unsolved issue in non-quantitative nutrition environment evaluation, and the nutrition environment of Chinese-style dining establishments has not been effectively assessed. This study developed two evaluation tools: the Nutrition Environment Scoring for Chinese Style University/Work-site Canteens (NESC-CC) and the Oil–Salt Visual Analogue Scale (OS-VAS) and applied them in nine university canteens. The NESC-CC, which includes comprehensive items from the healthiness of food availability, cooking methods to other factors that support healthy choices, is featured by adjusting the scoring categories and items to suit Chinese food culture and canteen operation model. The OS-VAS is a novel virtual analog scale (VAS) based on the fuzzy judgement of the diners. It requires the randomly recruited respondents to rate their personal preference for salty taste/greasy food preference, overall saltiness/greasiness of canteen dishes, and personal demands for salt/cooking oil reduction. The oil use score, the salt use score, and the total score are derived from the given formula. The field tests of the NESC-CC in nine university canteens at three time points showed that this tool was able to effectively distinguish the nutrition environment of the Chinese food-style canteens with good reliability and validity. The result of OS-VAS scoring achieved a good resolution of the overall salt and oil/fat use and confirmed our hypothesis on the fuzzy judgement of the diners These tools are suitable for the comprehensive evaluation of Chinese-style canteens and have the potential to be applied to more group-meal-providing establishments.

Background: This study aimed to estimate the impact of the COVID-19 lockdown on fitness performance among Chinese college men during the pandemic period and to explore how fitness changed with a different college grade. Methods: We conducted repeated measures of 1000 m running and pull-up testing on students from one university in China before and after the lockdown. A total of 7107 (age 19.21 ± 1.17 yr.) male students who completed the same 1000 m running and pull-up testing in 2019 and 2020 were included in the analysis. Results: The paired t-test result indicates a reduction in 1000 m running and pull-up performance by 10.91% (95% CI = 0.89, 0.95) and 23.89% (95% CI = −0.36, −0.31), respectively. Interestingly, college men in the 2017 grade (the third-year college men) had more decreases than in the 2019 grade (the first-year college men). The 1000 m running performance was decreased by 14.43% and 6.48% in the third- and the first-year college men, respectively. The pull-up performance was decreased by 39.11 % in the third-year college men while increased by 10.98% in the first-year college men. Conclusions: The COVID-19 lockdown reduced 1000 m running and pull-up performances among Chinese college men. The reduction varies by grade and it seems to be particularly seriously decreased for the third-year college men while being modest for the first-year college men. Public policy was urgently needed to improve Chinese college men’s fitness performance after the lockdown.

The simplification of truth table is of great significance to the analysis and design of logic circuits. In this paper, the simplification of truth table is studied, and a method of GDM (granular discernibility matrix) that uses discernibility matrix is proposed to obtain the minimum Boolean expression from truth table, and its application in logic optimization is realized. Firstly, the truth table is regarded as a logical information system and the simplification of truth table is transformed into the problem of finding the simplest rules of the logical information system. Then, based on the traditional discernibility matrix, the equivalent relation model is used to construct the GDM, the information granular that can be organized into the minimum Boolean expression is found, and the minimum Boolean expression of the logical information system is obtained by using the disjunctive and conjunction operation of the information granular. In order to accelerate the convergence speed of the algorithm, the heuristic information is introduced, and the decision rule of organizing information granular is given to avoid the occurrence of redundant logic items in the acquisition of the minimum Boolean expression, making Boolean logic expression simplest. The acquisition efficiency of the minimum Boolean expression is improved, and the problem of large-scale logic circuit optimization is solved. Finally, the algorithm is described in detail through an example, and its correctness is proven mathematically. Finally, a detailed algorithm is given, and the correctness and effectiveness of the method are demonstrated through examples and theoretical proofs.

Distributed Active Sensing Networks (DASNs) is a new sensing paradigm, where active and passive sensors are distributed in a field, and collaboratively detect the objects. The detectability is the most important property of DASNs. “Exposure” is defined to quantify the dimension limitations in detectability. Thus, it is important to deploy the sensors with the minimum exposure to improve the detectability. To minimize exposure is NP-hard, thus it is necessary to solve it by heuristic algorithms. In this paper, we present a Discrete Particle Swarm Optimization (DPSO)-based solution to achieve the minimum exposure. Furthermore, a feedback-based adjustment on the inertia weight of DPSO is designed to improve the convergence speed and global searching ability of algorithm. By a large number of simulations, this improved DPSO (Faiw-DPSO) is proved to outperform greedy algorithm by up to 74% and perform better than other related algorithms. This algorithm is robust, efficient and self-adaptive in regular and irregular monitoring field.

With the continuous development of technology, the structure of electronic circuit board is more complicated than in the past, the failure mode and failure mechanism are tend to be diversified, so that the maintenance of electronic circuit board is complicated, high requirements for maintenance personnel, and the time cost is high. However, the neural network can be used to diagnose the failure of the nonlinear complex system in the actual project. Therefore, the advantage of neural network in the field of intelligent diagnosis is taken in this paper, combined with genetic algorithm, an intelligent fault diagnosis method is proposed based on electronic circuit board parts. The test shows that the method has high accuracy.

Background The directional flow of injection through a Whitacre needle can be used to modify the level of sensory blockade. We hypothesized that injection of hyperbaric local anesthetic through a Whitacre needle with the bevel oriented laterally can produce a more symmetric sensory block. Methods Patients scheduled for lower limb surgery under spinal anesthesia with the patient in lateral decubitus position were randomized to receive 10 mg, 0.5% hyperbaric bupivacaine with the Whitacre needle orifice in 1 of 2 orientations, cephalad and lateral. The patient's position was maintained for 15 min after the injection, and sensory blocks were recorded. The primary outcome was the sensory levels between the dependent and nondependent side. The Wilcoxon-Mann-Whitney U-test odds was used to compare unpaired nonparametric data. For the paired samples, 95% confidence intervals (CI) of differences between group medians were calculated using the Hodges-Lehman estimator for the median difference in number of blocked segments. Results There was no significant difference in block level between dependent and nondependent sides in the lateral group. The Hodges-Lehmann point estimator was 0.5% and 95% CI was 0-2.5, suggesting a more symmetric sensory block in patients in the lateral decubitus position maintained for a sufficient period of time. A significantly lower level of blockade was noticed on the nondependent side compared to the dependent side in the cephalad group. The Hodges-Lehmann point estimator was 2.5 segments and 95% CI was 0.5-5. Conclusions Injection of 10 mg of 0.5% hyperbaric bupivacaine with the bevel of the Whitacre needle oriented laterally produces more symmetric sensory levels of blockade between the dependent and nondependent sides.

The rhizospheric bacterium JW-SD2 was identified as Pseudomonas frederiksbergensis based on phenotypic features, the Biolog Identification System and 16S rRNA sequence analysis. The phosphate-solubilizing activity, acidification in culture media, growth rate and organic acid secretion of JW-SD2 were investigated during 192 h of cultivation. The phosphate solubilized by JW-SD2 reached 7.75 mM. The decrease of pH and increase of titratable acidity were closely correlated (Pearson’s r = −0.953 and 0.969, respectively) with the phosphate-solubilizing activity. High concentrations of gluconic, 2-ketogluconic, pyruvic, maleic and malic acids were detected before 96 h of culture, when the strain displayed a high level of phosphate-solubilizing activity, indicating that these organic acids were efficient components in phosphate solubilization. However, acetic acid did not affect phosphate solubilization as shown by a remarkable increase at 144 h of culture when the phosphate-solubilizing activity decreased. The phosphate-solubilizing ability of JW-SD2 was significantly (P