The intelligent and automatic evaluation for teaching quality has been a more and more general demand in the digital society. The most intuitive solution is to make an assessment based on examination ...results, which cannot comprehensively reflect the course situation. To deal with such a problem, this paper designs a smart knowledge discovery system for teaching quality evaluation using a genetic algorithm-based BP neural network. Three aspects of factors are selected as the features: teaching conditions, teaching process, and teaching effect. The BP neural network is formulated to learn a nonlinear mapping from initial features to evaluation results. The learned parameters are then re-optimized by introducing the genetic algorithm. The proposed evaluation framework is also assessed concerning running performance on a real-world course-teaching dataset. The obtained results reflect that the proposal can realize the intelligent evaluation of the teaching effect and the evaluation effect is close to artificial experience-based evaluation results.
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•Stable and noble gas isotope compositions indicate a magmatic-hydrothermal origin of the ore-forming fluid.•Fluid cooling, phase separation, and mixing with meteoric waters are the ...important factors for ore deposition.•A porphyry ore system with proximal porphyry type Sn ± Cu ± Mo mineralization and peripheral Ag-Pb-Zn veins.
Many new discoveries of base and precious metal veins in the Great Hinggan Range district have made this region the most important Ag-Pb-Zn metallogenic belt in northern China. The Bianjiadayuan Ag-Pb-Zn deposit (4.81 Mt @157 g/t Ag and 3.94% Pb + Zn) is one of the new discoveries located in the southern segment of this potentially important but poorly understood metallogenic belt. Vein-type Ag-Pb-Zn ore bodies are predominantly hosted by slate adjacent to a Sn ± Cu ± Mo mineralized porphyry intrusion. Four primary ore stages of arsenopyrite + pyrite + quartz, main sulfides + quartz, silver-bearing sulfosalts + quartz, and boulangerite + calcite are recognized, and a subsequent supergene oxidation stage has also been identified. An alteration assemblage of quartz, sericite, chlorite and epidote is spatially associated with this vein type mineralization. The δDH2O (−139 to −106‰) and δ18OH2O (−16.4 to 12.1‰) isotope compositions obtained from different stage vein quartz and calcite reveal that the early stage ore fluids were dominated by magmatic fluids, whereas the late stage ore fluids contained a significant proportion of meteoric waters, which is consistent with the δ13CPDB (−7.7 to −2.7‰) and δ18OSMOW (−0.4 to 6.4‰) isotope signatures for waning stage calcites reflecting an addition of large volumes of meteoric waters in hydrothermal system. Noble gas isotopes (i.e., 3He/4He ratios of 1.52–3.06 Ra) display evidences of a magmatic fluid responsible for ore formation in the deposit. Fluid inclusion studies suggest that vein formation occurred at progressively lower temperature (310–220 °C) and pressure (100–20 bars). Fluid cooling, phase separation, and mixing with meteoric waters are advocated as the important factors for ore deposition. In combination, available data for the Bianjiadayuan deposit suggest that local Ag-Pb-Zn veins and porphyry type Sn ± Cu ± Mo mineralization are genetically related and formed in one porphyry ore system, which is a useful concept for local and regional Ag-Pb-Zn exploration.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Background: Cross-company defect prediction (CCDP) is a field of study where an organization lacking enough local data can use data from other organizations for building defect predictors. To support ...CCDP, data must be shared. Such shared data must be privatized, but that privatization could severely damage the utility of the data. Aim: To enable effective defect prediction from shared data while preserving privacy. Method: We explore privatization algorithms that maintain class boundaries in a dataset. CLIFF is an instance pruner that deletes irrelevant examples. MORPH is a data mutator that moves the data a random distance, taking care not to cross class boundaries. CLIFF+MORPH are tested in a CCDP study among 10 defect datasets from the PROMISE data repository. Results: We find: 1) The CLIFFed+MORPHed algorithms provide more privacy than the state-of-the-art privacy algorithms; 2) in terms of utility measured by defect prediction, we find that CLIFF+MORPH performs significantly better. Conclusions: For the OO defect data studied here, data can be privatized and shared without a significant degradation in utility. To the best of our knowledge, this is the first published result where privatization does not compromise defect prediction.
Passive surface wave methods that utilize ambient noise to investigate underground space have been widely used in densely populated urban areas. As an important step in imaging from ambient noise, ...dispersion measurement seriously affects the accuracy of the final inversion results. Linear stacking, the most commonly used stacking method in dispersion measurement, usually relies on the long observation time to obtain Green's functions with high signal-to-noise. However, it is sometimes difficult to ensure sufficient observation time for passive surface wave methods for exploration efficiency and environmental restrictions in urban areas, making dispersion measurement from ultra-short noise important and necessary. Considering the limitations of linear stacking, we compared the dispersion images obtained by linear stacking, phase-weighted stacking (PWS), and time-frequency phase-weighted stacking using ultra-short ambient noise to find an appropriate stacking way. Synthetic experiments show that PWS can obtain better cross-correlation functions and dispersion spectra with fewer noise segments. Two field cases further verify the reliability of applying PWS in dispersion measurement from several minutes of the continuous noise record by analyzing the phase velocities error or comparing the inversion results with the drilling data. Both synthetic experiments and field examples illustrate PWS can be used as an efficient and economical method to meet the needs of ultra-short-time imaging and real-time monitoring of urban underground structures.
•We compare and analyze the performance of PWS, linear stacking and tf-PWS.•PWS is best for the dispersion measurement from ultra-short traffic noise.•PWS has a strong denoising ability.•PWS can achieve a similar effect as long-time linear stacking.•Several minutes continuous noise can obtain the dispersion energy with high SNR.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
2019 and 2020 represent a decisive period for completing the building of a moderately prosperous society in all aspects. Therefore, it is important to prioritize the development of agriculture and ...rural areas to accomplish this historic mission. The Chinese government needs to properly handle the relations between urban-rural integration and the prior development of agriculture and rural areas, between long-term goals and short-term objectives, between general requirements and key breakthroughs, and between enabling the market to play a decisive role in resource allocation and making the government's role more effective. The most important tasks with respect to agriculture, rural areas, and rural people shall be fulfilled to prioritize the development of agriculture and rural areas.The report delivered at the 19th National Congress of the Communist Party of China (CPC) in 2017 proposed implementing the rural vitalization strategy. The No.1 Central Document of 2019 further emphasized the development of agriculture and rural areas. At this critical moment, prioritizing the development of agriculture and rural areas, and accomplishing the urgent tasks with regard to agriculture, rural areas, and rural people are fundamental to the effective response to all types of risks and challenges, and a sustainable and healthy economy, and overall social stability.
Gut microbiota has diverse ecological and evolutionary effects on its hosts. However, the ways in which it responds to environmental heterogeneity and host physiology remain poorly understood. To ...this end, we surveyed intestinal microbiota of Holotrichia parallela larvae at different instars and from different geographic regions. Bacterial 16S rRNA gene clone libraries were constructed and clones were subsequently screened by DGGE and sequenced. Firmicutes and Proteobacteria were the major phyla, and bacteria belonging to Ruminococcaceae, Lachnospiraceae, Enterobacteriaceae, Desulfovibrionaceae and Rhodocyclaceae families were commonly found in all natural populations. However, bacterial diversity (Chao1 and Shannon indices) and community structure varied across host populations, and the observed variation can be explained by soil pH, organic carbon and total nitrogen, and the climate factors (e.g., mean annual temperature) of the locations where the populations were sampled. Furthermore, increases in the species richness and diversity of gut microbiota were observed during larval growth. Bacteroidetes comprised the dominant group in the first instar; however, Firmicutes composed the majority of the hindgut microbiota during the second and third instars. Our results suggest that the gut's bacterial community changes in response to environmental heterogeneity and host's physiology, possibly to meet the host's ecological needs or physiological demands.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
High ionic conductivity and excellent alkaline stability are very important for solid electrolyte. Therefore, spindle-shaped anion exchange membranes (AEMs) based on poly (arylene ether ketone) and ...1-Bromo-N,N,N-trimethylhexane-6-aminium bromide (Br-QA) have been prepared. The obtained Br-QA can be grafted with poly (arylene ether ketone) main chains to form micro-phase separation structure enhancing the ionic conductivity. Especially, the grafting quaternary ammonium (QA) cation groups are separated by alkyl bromine endows the AEMs with alkaline stability features. Simultaneously, the OH− conductivity of the QA-PAEK-0.6 obtained membranes is 0.046 S/cm under fully hydrated conditions at 60 °C. After immersing into 1 M NaOH alkaline solution for 15 days at 60 °C, the anionic conductivity still high to 0.03 S/cm. Meanwhile, the poly (arylene ether ketone) backbones provide excellent mechanical properties and the Br-QA cation groups also possess good thermal stability, which satisfy the requirement of wide applications.
•The spindle-shaped membranes are synthesized.•Exhibit micro-phase separation structure to improve conductivity.•The alkaline stability of QA was improved by using a six carbon (–CH2–) spacers.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
During the COVID-19 pandemic, organizations need to effectively manage changes, and employees need to proactively adapt to these changes. The present research investigated when and how individual ...employees' narcissism was related to their change-oriented organizational citizenship behavior. Specifically, based on a trait activation perspective, this research proposed the hypotheses that individual employees' narcissism and environmental uncertainty would interactively influence employees' change-oriented organizational citizenship behavior via felt responsibility for constructive change; furthermore, the effect of narcissism on change-oriented organizational citizenship behavior via felt responsibility for constructive change would be stronger when the environmental uncertainty prompted by the COVID-19 pandemic was high rather than low. Two studies were conducted to test these hypotheses: an online survey of 180 employees in mainland China (Study 1) and a field study of 167 leader-follower dyads at two Chinese companies (Study 2). The current research reveals a bright side of narcissism, which has typically been recognized as a dark personality trait, and enriches the understanding of the antecedents of change-oriented organizational citizenship behavior. This research can also guide organizations that wish to stimulate employee proactivity.
Abstract In recent years, microplastic contamination has received worldwide distribution and specific attention. As a result, detecting sensitive bioindicators is crucial to establish the pollution. ...The aim of the present study is to investigate the accumulation of microplastics in zebra mussels ( Dreissena polymorpha , Pallas, 1771) from the sand pit lake Kazichene. The natural range of the zebra mussel in Bulgaria includes the Danube River delta, the Black Sea rivers and coastal lakes. However, it is considered a wide spread invasive species to inland freshwaters. The use of invasive species as bioindicators over native species is advisable in order to protect the local biodiversity. In total 20 mussels of D. polymorpha were used for the analysis. The biological tissues of the mussels were digested with the aid of 30% H 2 O 2 at 65°C for 24 - 48 hours. Microplastics (772 pcs. in total) were detected in all zebra mussel samples, indicating microplastic contamination in Lake Kazichene. Three main shapes have been identified: fragments, fibres and pellets, with the highest proportion of the fragments. The colours of the microplastic particles found were black, red, yellow and transparent, dominated by those of black colour, followed by red. The length of the fibres found in the zebra mussels ranged from 0.25 to 5 mm. There was no strong correlation between the body length/meat weight of zebra mussels with the degree of microplastic accumulation in the mussels.
The occurrence of osteoarthritis (OA) is highly associated with the reduced lubrication property of the joint, where a progressive and irreversible damage of the articular cartilage and consecutive ...inflammatory response dominate the mechanism. In this study, bioinspired by the super-lubrication property of cartilage and catecholamine chemistry of mussel, we successfully developed injectable hydrogel microspheres with enhanced lubrication and controllable drug release for OA treatment. Particularly, the lubricating microspheres (GelMA@DMA-MPC) were fabricated by dip coating a self-adhesive polymer (DMA-MPC, synthesized by free radical copolymerization) on superficial surface of photo-crosslinked methacrylate gelatin hydrogel microspheres (GelMA, prepared via microfluidic technology), and encapsulated with an anti-inflammatory drug of diclofenac sodium (DS) to achieve the dual-functional performance. The tribological test and drug release test showed the enhanced lubrication and sustained drug release of the GelMA@DMA-MPC microspheres. In addition, the functionalized microspheres were intra-articularly injected into the rat knee joint with an OA model, and the biological tests including qRT-PCR, immunofluorescence staining assay, X-ray radiography and histological staining assay all revealed that the biocompatible microspheres provided significant therapeutic effect against the development of OA. In summary, the injectable hydrogel microspheres developed herein greatly improved lubrication and achieved sustained local drug release, therefore representing a facile and promising technique for the treatment of OA.
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•One step dip coating method was developed to prepare lubricated injectable hydrogel microspheres.•The interfacial lubrication mechanism of the injectable hydrogel microspheres was due to hydration lubrication.•The hydrogel microspheres were effective for the treatment of osteoarthritis via the in vitro and in vivo tests.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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