344 research outputs found
Study on the weight coefficient influence of surface water on the stability of open-pit dump. Comparative analysis of 6 degree seismic simulation
Taking Baorixile open-pit coal mine as an example, the regional hydrogeological conditions and the mining area hydrogeological conditions are briefly introduced. Analyzing the factors influencing the stability of open pit dump, discussing the classification and proportion of influencing factors, the numerical simulation of the influence of surface water and seismic vibrations on the stability of open-pit dump is carried out. Results show: Surface water is an important factor affecting the stability of open-pit dump, extremely sensitive to the safety factor, the influence of slope instability is similar to that of intensity 6 earthquake. The weight coefficient of surface water to slope stability is in the range of 0.4 to 0.9
Experimental Visualization of the Icing Process of Water Droplets on Cold Aluminum Plate Surface
Ice accretion on the cold airfoil blade surface, such as wind turbines working in winter, affects its performance and degrades its aerodynamic characteristics and efficiency. Therefore, it is necessary to study the icing characteristics on the cold blade surface. At present, many pieces of research on wind turbine blade icing have been explored on the macroscale but seldom on the microscale. In this chapter, the icing process of a single water droplet on the cold aluminum plate surface was examined by a visualized method. The effects of volume and temperature on the icing characteristics were tested and acquired. After that, the profile parameters of iced water droplets were drawn and analyzed by MATLAB software, including the contact diameter, the maximum diameter and height of iced water droplets, the contact angle, and so on. The research findings provide experimental and theoretical foundations to deeply study the icing characteristics of wind turbine blades on a microscale
Preparation of Iron-nickel Alloy Nanostructures via Two Cationic Pyridinium Derivatives as Soft Templates
In this paper, crystalline iron-nickel alloy nanostructures were successfully prepared from two cationic pyridinium derivatives as soft templates in solution. The crystal structure and micrograph of FeNi alloy nanostructures were characterized by X-ray diffraction, scanning electron microscopy and transmission electron microscopy, and the content was confirmed by energy-dispersive spectrometry. The results indicated that the as-prepared nanostructures showed slightly different diameter ranges with the change of cationic pyridinium derivatives on the surface. The experimental data indicated that the adsorption of cationic pyridinium compounds on the surface of particles reduces the surface charge, leading to an isotropic distribution of the residual surface charges. The magnetic behaviours of as-prepared FeNi alloy nanostructures exhibited disparate behaviours, which could be attributed to their grain sizes and distinctive structures. The present work may give some insight into the synthesis and character of new alloy nanomaterials with special nanostructures using new soft templates
Evaluation on the psychological adjustment and countermeasures of civil servants in public emergencies
Public health emergencies are inevitable major development crises, and there are almost no omens of any emergency. The current social development would inevitably affect the psychological situation of civil servants. Grass roots civil servants have a wider range of tasks, more difficult working conditions and a more difficult environment. Under the strong social pressure, civil servants would also have negative factors such as fear and negative attitude. The mental health of grass-roots civil servants depends not only on the image and efficiency of the government, but also on creating a harmonious atmosphere and the quality of economic development. Therefore, people must pay attention to the psychological health of civil servants. It is mainly through psychological intervention and psychological adjustment to improve mental health. By analyzing the psychological characteristics of civil servants under emergencies and under pressure, and according to the importance of their coping ability under emergencies, this paper conducted corresponding psychological adjustment and psychological intervention to ensure the psychological health of civil servants, improve their ability to deal with public emergencies, and enable them to use correct and positive psychology to deal with public emergencies. It can be seen from the firefly algorithm that the prediction error value of the comprehensive quality of civil servants was declining, while the evaluation effect of the comprehensive quality was rising. The average value of the prediction error value of the comprehensive quality was about 0.49, and the average value of the evaluation effect of the comprehensive quality was about 0.73. In the whole process, the prediction error value of comprehensive quality decreased by 0.37, and the evaluation effect of comprehensive quality increased by 0.33. The comprehensive psychological quality and psychological adjustment ability of civil servants after psychological intervention were better than those before psychological intervention. The comprehensive psychological quality of civil servants after psychological intervention was 8.56% higher than that before psychological intervention, and the psychological adjustment ability was 8.47% higher than that before psychological intervention
Differential expression of miRNAs related to caste differentiation in the honey bee, Apis mellifera
International audienceAbstractHoney bees are very important eusocial insects and are involved in the pollination of many plants. Queen bees and worker bees can develop from the same fertilized eggs and are thus genetically identical despite their substantial behavioral and physiological differences. The mechanism governing developmental differences between worker and queen bees has always attracted much interest. While there are several reports on messenger RNA (mRNA) expression related to caste differentiation or microRNA (miRNA) expression in one time point of caste differentiation, no systematic investigation of the dynamic expression of small RNAs along with these two caste development has, thus far, been carried out. In this study, we present the dynamic expression profiles of queen and worker bee small RNAs and show caste-specific miRNA expression patterns between them, indicating that miRNAs may be related to the differential development of worker and queen bee larvae. Results presented here will make a valuable contribution to understanding of the caste switch between worker and queen bees
Inhibitory effects of Clostridium butyricum culture and supernatant on inflammatory colorectal cancer in mice
Clostridium butyricum (CB) is a spore-forming, gram-positive and obligate anaerobic rod bacterium. CB can modulate the composition of the gut microbiome and promote the growth of beneficial microbes in the intestine by generating short-chain fatty acids (SCFAs), which in turn protect against colitis and prevents the formation of inflammatory-associated colorectal cancer (CRC) by ameliorating colon inflammatory processes. Yet, it remains unclear whether the culture and supernatant of CB could directly influence inflammatory CRC in mice. In this study, azoxymethane (AOM)+dextran sodium sulphate (DSS) was used to induce CRC model in C57BL/6 mice. Next, the serum levels of inflammatory cytokines, including interleukin-6 (IL-6), interleukin-10 (IL-10), and cytokines TNF-α, were measured and the pathohistological examination of the large intestine was performed. Both CB culture and supernatant were found to have anti-inflammatory properties. Subsequently, Western blot and Real-Time Quantitative PCR (RT-qPCR) revealed that CB and supernatant regulate the NF-κB/p65 pathway to inhibit the development and progression of inflammatory CRC in AOM+DSS-treated mice, which could be due to the high levels of butyric acid in the supernatant
Modelling of plasma response to 3D external magnetic field perturbations in EAST
Sustained mitigation and/or suppression of type-I edge localized modes (ELMs) has been achieved in EAST high-confinement plasmas, utilizing the resonant magnetic perturbation (RMP) fields produced by two rows of magnetic coils located just inside the vacuum vessel. Systematic toroidal modelling of the plasma response to these RMP fields with various coil configurations (with dominant toroidal mode number n = 1, 2, 3, 4) in EAST is, for the first time, carried out by using the MARS-F code (Liu et al 2000 Phys. Plasmas 7 3681), with results reported here. In particular, the plasma response is computed with varying coil phasing (the toroidal phase difference of the coil currents) between the upper and lower rows of coils, from 0 to 360°. Four figures of merit, constructed based on the MARS-F computations, are used to determine the optimal coil phasing. The modelled results, taking into account the plasma response, agree well with the experimental observations in terms of the coil phasing for both the mitigated and the suppressed ELM cases in EAST experiments. This study provides a crucial confirmation of the role of the plasma edge peeling response in ELM control, complementing similar studies carried out for other tokamak devices
Recipe for a Busy Bee: MicroRNAs in Honey Bee Caste Determination
Social caste determination in the honey bee is assumed to be determined by the dietary status of the young larvae and translated into physiological and epigenetic changes through nutrient-sensing pathways. We have employed Illumina/Solexa sequencing to examine the small RNA content in the bee larval food, and show that worker jelly is enriched in miRNA complexity and abundance relative to royal jelly. The miRNA levels in worker jelly were 7-215 fold higher than in royal jelly, and both jellies showed dynamic changes in miRNA content during the 4(th) to 6(th) day of larval development. Adding specific miRNAs to royal jelly elicited significant changes in queen larval mRNA expression and morphological characters of the emerging adult queen bee. We propose that miRNAs in the nurse bee secretions constitute an additional element in the regulatory control of caste determination in the honey bee.The research was supported by National Sciences Foundation of China Grant No.30630040; National Key Basic Research & Development Program 973 under Grant Nos. 2009CB825401 and 2007CB946901 to RSC, the earmarked fund for Modern Agro-industry Technology Research System (No. CARS-45-KXJ3), and a grant of the National Natural Science Foundation of China (NSFC 30571409) to SKS, and the Nature and Science Foundation Commission of Zhejiang Province (R3080306) to SKS. Zhang was supported by the Australian Research Council through the ARC Centre of Excellence in Vision Science (CE0561903). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript
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