939 research outputs found

    Teaching Evaluation System on Engineering for Applied University in China

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    This research presents a novel Teaching Evaluation System model designed to enhance the quality of education in Chinese applied universities with a focus on engineering programs. The objectives included synthesizing relevant theories related to teaching evaluation systems in applied university engineering and developing a comprehensive system. A population of 9 experts from China was selected through purposive sampling, all qualified and with a minimum of five years' experience as Assistant Professors at the same university. SPSSPRO was employed for data assessment, ensuring questionnaire reliability with a Cronbach's ? of .823, indicating excellent reliability. The research result, with an average score of 4.6358, SD. = 0.4655, CV = .1008, IQR = 1, demonstrated a strong agreement among expert opinions. Utilizing the Analytic Hierarchy Process (AHP) for weighting analysis and assessing matrix consistency, CR = .039 < .1, suggested sufficient consistency for decision-making. The research employed focus groups to discuss the evaluation system for Chinese applied university engineering education, utilizing the CIPP model, modifying the evaluation index system, and employing AHP for indicator ranking. A case study at Sichuan University of Science & Engineering, using the new evaluation index system, revealed program issues, and offered recommendations. The index system comprises four first-level, 12 second-level, and 52 third-level indexes, providing a reflective evaluation of the actual relationships among indicators and serving as a valuable reference for assessing engineering education quality

    An improved differential evolution algorithm and its applications to orbit design

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    Differential Evolution (DE) is a basic and robust evolutionary strategy that has been applied to determining the global optimum for complex optimization problems[1–5]. It was introduced in 1995 by Storn and Price [1] and has been successfully applied to optimization problems including nonlinear, non-differentiable, non-convex, and multi-model functions. DE algorithms show good convergence, high-reliability, simplicity, and a reduced number of controllable parameters [2]. Olds and Kluever [3] applied DE to an interplanetary trajectory optimization problem and demonstrated the effectiveness of DE to produce rapid solutions. Madavan [4] discussed various modifications to the DE algorithm, improved its computational efficiency, and applied it to aerodynamic shape optimization problems. DE algorithms are easy to use, as they require only a few robust control variables, which can be drawn from a well-defined numerical interval. However, the existing various DE algorithms also have limitations, being susceptible to instability and getting trapped into local optima[2]. Notable effort has been spent addressing this by coupling DE algorithms with other optimization algorithms (for example, Self Organizing Maps (SOM) [6], Dynamic Hill Climbing (DHC) [7], Neural Networks (NN) [7], Particle Swarm Optimization (PSO) [8]). In these cases, the additional algorithm is used as an additional loop within the optimization process, creating a hybrid system with an inner and outer loop. Such hybrid algorithms are inherently more complex and so the computation cost is increased. Attempting to address this, a self-adaptive DE was designed and applied to the orbit design problem for prioritized multiple targets by Chen[5]. However, the self-adaptive feature is somewhat limited as it relates only to the number of generations within the optimization. A Self-adaptive DE which can automatically adapt its learning strategies and the associated parameters during the evolving procedure was proposed by Qin and Suganthan[9] and 25 test functions were used to verify the algorithm

    Polymorphisms of the IGF1R gene and their genetic effects on chicken early growth and carcass traits

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    <p>Abstract</p> <p>Background</p> <p>The insulin-like growth factor I receptor (IGF1R) has an important effect on growth, carcass, and meat quality traits in many species. However, few studies on associations of the <it>IGF1R </it>gene with growth and carcass traits have been reported in chickens. The objectives of the present study were to study the associations of the <it>IGF1R </it>gene with chicken early growth and carcass traits using a neutral test, variation scan of the gene, genetic diversity, linkage disequilibrium and association analyses.</p> <p>Results</p> <p>The tree generated from the amino acid sequences of 15 species showed that the <it>IGF1R </it>gene was conservative in the whole evolution among the mammalian animals and chickens. In a total of 10,818 bp of sequence, 70 single nucleotide polymorphisms were identified in the chicken <it>IGF1R </it>gene. The allelic and genotypic frequency distribution, genetic diversity and linkage disequilibrium of 18 single nucleotide polymorphisms (SNPs) in the Xinghua and White Recessive Rock chickens showed that six of them were possibly associated with growth traits. Association analyses showed that the A17299834G SNP was significantly associated with chicken carcass body weight, eviscerated weight with giblets, eviscerated weight, body weights at 28, 35, and 56 d of age, leg length at 56 d of age, and daily weight gain at 0–4 weeks. The haplotypes of the A17307750G and A17307494G were associated with early growth traits. The haplotypes of the A17299834G and C17293932T were significantly associated with most of the early growth traits and carcass traits.</p> <p>Conclusion</p> <p>There were rich polymorphisms in the chicken <it>IGF1R </it>gene. Several SNPs associated with chicken early growth traits and carcass traits were identified in the <it>IGF1R </it>gene by genetic diversity, linkage disequilibrium, and association analyses in the present study.</p

    Nanoindentation Characterization of a Ternary Clay-Based Composite Used in Ancient Chinese Construction

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    Ternary clay-based composite material (TCC), composed of lime, clay and sand, and usually modified with sticky rice and other organic compounds as additives, was widely used historically in Chinese construction and buildings due to its high mechanical performance. In this study, to gain an insight into the micromechanical mechanism of this cementitious material, the nanomechanical properties and volume fraction of mechanically different phases of the binder matrix are derived from the analysis of grid nanoindentation tests. Results show that there are five distinct mechanical phases, where the calcium silicate hydrate (C-S-H) and geopolymer present in the binder matrix are almost identical to those produced in ordinary Portland cement (OPC) and alkali-activated fly-ash geopolymer materials in nano-mechanical performance. The nano-mechanical behavior of calcite produced by the carbonation of lime in this binder is close to the calcite porous outer part of some sea urchin shells. Compared to OPC, the C-S-H contained in the TCC has a relatively lower ratio of indentation modulus to indentation hardness, implying a relatively lower resistance to material fracture. However, the geopolymer and calcite, at nearly the same volume content as the C-S-H, help to enhance the strength and durability of the TCC by their higher energy resistance capacity or higher strength compared to the C-S-H. Rediscovering of TCC offers a potential way to improve modern concrete’s strength and durability through synergy of multi-binders and the addition of organic materials if TCC can be advanced in terms of its workability and hardening rate

    Potential roles of the gut microbiota in the manifestations of drug use disorders

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    Drug use disorders (DUDs) not only cause serious harm to users but also cause huge economic, security, and public health burdens to families and society. Recently, several studies have shown that gut microbiota (GM) can affect the central nervous system and brain functions. In this review, we focus on the potential role of the GM in the different stages of DUDs. First, the GM may induce individuals to seek novel substances. Second, the gut microbiota is involved in the decomposition and absorption of drugs. Symptoms of individuals who suffer from DUDs are also related to intestinal microorganisms. Third, the effects of the GM and its metabolites on drug relapse are mainly reflected in the reward effect and drug memory. In conclusion, recent studies have preliminarily explored the relationship between GM and DUDs. This review deepens our understanding of the mechanisms of DUDs and provides important information for the future development of clinical treatment for DUDs

    Upconversion Luminescence Properties of Y 2

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    The Yb3+, Er3+ doped Y2O3 and Y2O2S upconversion nanophosphors were prepared by the direct complex precipitation method with the mixed solution of NH4HCO3 and NH3·H2O as the complex precipitant. The precipitate of ReOHxCO3y calcined at 900°C in air presents the pure Y2O3 with cubic structure, and the calculated crystalline size is about 26 nm, while the Y2O2S:Yb, Er nanocrystals were obtained by annealing the same precipitate at 900°C but in the atmosphere of N2 gas containing sulfur vapor. The obtained sample presents the pure hexagonal structure of Y2O2S with calculated crystalline size of 29 nm. According to the transmission electronic microscopy (TEM), the nanophosphors exhibit uniform quasispherical shape and size about 30 nm. By using the 980 nm excitation laser, the properties of upconversion luminescence and energy transfer processes were studied in detail for the different concentration of Yb3+ in Er3+ doped Y2O3 as well as the Yb3+, Er3+ codoped Y2O2S nanocrystals. The high-efficient red and yellow upconversion emissions were both observed by naked eyes in day time corresponding to the Y2O3:Yb, Er and Y2O2S:Yb, Er phosphors, respectively. Thus the upconversion nanoparticles combining its high efficient emission would pave the way for ideal fluorescence probes in biological applications
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