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  • 1
    Language: English
    In: E3S web of conferences, 2020, Vol.165, p.4010
    Description: This paper introduces the basic functions and characteristics of the Rain Classroom platform based on information technology. By using the integration of information technology and Control Engineering course teaching, a mixed teaching mode of control engineering course based on Rain Classroom is designed and applied to specific teaching practice. The results show that, the engineering thinking, learning habits, self-learning ability, learning interest and learning enthusiasm of the experimental class have been greatly improved compared with before after the practice of blended teaching.
    ISSN: 2267-1242
    E-ISSN: 2267-1242
    Source: Directory of Open Access Journals
    Source: Alma/SFX Local Collection
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  • 2
    Language: English
    In: Environmental management (New York), 2011-12, Vol.48 (6), p.1158-1172
    Description: Conversion of cropland into perennial vegetation land can increase soil organic carbon (SOC) accumulation, which might be an important mitigation measure to sequester carbon dioxide from the atmosphere. The “Grain for Green” project, one of the most ambitious ecological programmes launched in modern China, aims at transforming the low-yield slope cropland into grassland and woodland. The Loess Plateau in China is the most important target of this project due to its serious soil erosion. The objectives of this study are to answer three questions: (1) what is the rate of the SOC accumulation for this “Grain for Green” project in Loess Plateau? (2) Is there a difference in SOC sequestration among different restoration types, including grassland, shrub and forest? (3) Is the effect of restoration types on SOC accumulation different among northern, middle and southern regions of the Loess Plateau? Based on analysis of the data collected from the literature conducted in the Loess Plateau, we found that SOC increased at a rate of 0.712 TgC/year in the top 20 cm soil layer for 60 years under this project across the entire Loess Plateau. This was a relatively reliable estimation based on current data, although there were some uncertainties. Compared to grassland, forest had a significantly greater effect on SOC accumulation in middle and southern Loess Plateau but had a weaker effect in the northern Loess Plateau. There were no differences found in SOC sequestration between shrub and grassland across the entire Loess Plateau. Grassland had a stronger effect on SOC sequestration in the northern Loess Plateau than in the middle and southern regions. In contrast, forest could increase more SOC in the middle and southern Loess Plateau than in the northern Loess Plateau, whereas shrub had a similar effect on SOC sequestration across the Loess Plateau. Our results suggest that the “Grain for Green” project can significantly increase the SOC storage in Loess Plateau, and it is recommended to expand grassland and shrub areas in the northern Loess Plateau and forest in the middle and southern Loess Plateau to enhance the SOC sequestration in this area.
    Subject(s): Grassland ; SOC ; Shrub ; Ecology ; General linear model ; Nature Conservation ; Restoration age ; Forestry Management ; Environment ; Forest ; Waste Water Technology / Water Pollution Control / Water Management / Aquatic Pollution ; Atmospheric Protection/Air Quality Control/Air Pollution ; Environmental Management ; Carbon - metabolism ; Climate ; Poaceae - metabolism ; China ; Edible Grain - metabolism ; Soil - chemistry ; Agriculture ; Conservation of Natural Resources ; Poaceae - growth & development ; Loess ; Soils ; Tundra ecology ; Greenhouse effect ; Soil erosion ; Carbon content ; Analysis ; Carbon dioxide ; Niche (Ecology) ; Index Medicus
    ISSN: 0364-152X
    E-ISSN: 1432-1009
    Source: Alma/SFX Local Collection
    Source: © ProQuest LLC All rights reserved〈img src="https://exlibris-pub.s3.amazonaws.com/PQ_Logo.jpg" style="vertical-align:middle;margin-left:7px"〉
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  • 3
    Language: English
    In: The Visual computer, 2021-03, Vol.37 (3), p.515-528
    Description: The automatic detection of defects is an important part of the fabric production process. However, existing methods of detecting defects in fabrics with periodic patterns lack adaptability and perform poorly in detection. In this paper, we propose an unsupervised fabric defect detection method based on the human visual attention mechanism. The method introduces two-dimensional entropy which can reflect the spatial distribution characteristics of images based on one-dimensional entropy, according to the relationship between information entropy and image texture. The image is reconstructed into a quaternion matrix by combining two-dimensional entropy and three feature maps that characterize the opponent color space representation of the input image. The hypercomplex Fourier transform is then used to transform the quaternion image matrix into the frequency domain. We propose a new method for local tuning of amplitude spectrum, thereby suppressing the background pattern while retaining the defect region. Finally, the inverse transform is performed to obtain a saliency map. Through experimental comparisons and a series of numerical evaluations, we demonstrate that the proposed method has a better detection effect compared to state-of-the-art methods in fabric defect detection.
    Subject(s): Textile fabrics ; Mechanical engineering ; Analysis ; Feature maps ; Fourier transforms ; Spatial distribution ; Quaternions ; Production methods ; Entropy (Information theory) ; Salience ; Entropy ; Image reconstruction ; Frequency domain analysis ; Defects
    ISSN: 0178-2789
    E-ISSN: 1432-2315
    Source: Alma/SFX Local Collection
    Source: © ProQuest LLC All rights reserved〈img src="https://exlibris-pub.s3.amazonaws.com/PQ_Logo.jpg" style="vertical-align:middle;margin-left:7px"〉
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  • 4
    Language: English
    In: Global change biology, 2018-08, Vol.24 (8), p.3537-3545
    Description: Autumn phenology remains a relatively neglected aspect in climate change research, which hinders an accurate assessment of the global carbon cycle and its sensitivity to climate change. Leaf coloration, a key indicator of the growing season end, is thought to be triggered mainly by high or low temperature and drought. However, how the control of leaf coloration is split between temperature and drought is not known for many species. Moreover, whether growing season and autumn temperatures interact in influencing the timing of leaf coloration is not clear. Here, we revealed major climate drivers of leaf coloration dates and their interactions using 154 phenological datasets for four winter deciduous tree species at 89 stations, and the corresponding daily mean/minimum air temperature and precipitation data across China's temperate zone from 1981 to 2012. Results show that temperature is more decisive than drought in causing leaf coloration, and the growing season mean temperature plays a more important role than the autumn mean minimum temperature. Higher growing season temperature and lower autumn minimum temperature would induce earlier leaf coloration date. Moreover, the mean temperature over the growing season correlates positively with the autumn minimum temperature. This implies that growing season mean temperature may offset the requirement of autumn minimum temperature in triggering leaf coloration. Our findings deepen the understanding of leaf coloration mechanisms in winter deciduous trees and suggest that leaf life‐span control depended on growing season mean temperature and autumn low temperature control and their interaction are major environmental cues. In the context of climate change, whether leaf coloration date advances or is delayed may depend on intensity of the offset effect of growing season temperature on autumn low temperature. Autumn phenology remains a relatively neglected aspect in climate change research, which hinders an accurate assessment of the global carbon cycle and its sensitivity to climate change. Here, we revealed relationships between leaf coloration dates of four winter deciduous tree species and three climatic factors through partial correlation and linear regression analyses at 89 stations across China's temperate zone from 1981 to 2012. Our findings suggest that leaf life‐span control depended on growing season mean temperature and autumn low temperature control and their interaction are major environmental cues of leaf coloration date in winter deciduous trees.
    Subject(s): environmental cues ; low temperature control ; precipitation ; climate change impacts ; air temperature ; drought‐stress control ; leaf life‐span control ; autumn plant phenology ; Temperature ; Color ; Populus - physiology ; Pigmentation ; Salix - physiology ; Trees - physiology ; Climate Change ; Droughts ; China ; Ulmus - physiology ; Robinia - physiology ; Seasons ; Plant Leaves - physiology ; Analysis ; Global temperature changes ; Precipitation (Meteorology) ; Index Medicus
    ISSN: 1354-1013
    E-ISSN: 1365-2486
    Source: Alma/SFX Local Collection
    Source: © ProQuest LLC All rights reserved〈img src="https://exlibris-pub.s3.amazonaws.com/PQ_Logo.jpg" style="vertical-align:middle;margin-left:7px"〉
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  • 5
    Language: English
    In: ChemSusChem, 2016-10-20, Vol.9 (20), p.2878-2904
    Description: Semiconducting heterostructures are emerging as promising light absorbers and offer effective electron–hole separation to drive solar chemistry. This technology relies on semiconductor composites or photoelectrodes that work in the presence of a redox mediator and that create cascade junctions to promote surface catalytic reactions. Rational tuning of their structures and compositions is crucial to fully exploit their functionality. In this review, we describe the possibilities of applying the two‐photon concept to the field of solar fuels. A wide range of strategies including the indirect combination of two semiconductors by a redox couple, direct coupling of two semiconductors, multicomponent structures with a conductive mediator, related photoelectrodes, as well as two‐photon cells are discussed for light energy harvesting and charge transport. Examples of charge extraction models from the literature are summarized to understand the mechanism of interfacial carrier dynamics and to rationalize experimental observations. We focus on a working principle of the constituent components and linking the photosynthetic activity with the proposed models. This work gives a new perspective on artificial photosynthesis by taking simultaneous advantages of photon absorption and charge transfer, outlining an encouraging roadmap towards solar fuels. Burning bright: Progress on two‐photon semiconducting structures is presented with focus on understanding of interfacial carrier dynamics. Strategies from solution‐particle photocatalytic systems to nanostructured photoelectrode and photoelectrochemical devices are discussed to elucidate the mechanism of charge transport and to rationalize experimental observations. The studies compile valuable knowledge to build efficient solar‐driven systems for clean energy.
    Subject(s): solar fuels ; photosynthesis ; heterojunctions ; semiconductors ; charge transport ; Solar Energy ; Photons ; Oxidation-Reduction ; Semiconductors ; Photosynthesis ; Light ; Phytochemistry ; Index Medicus
    ISSN: 1864-5631
    E-ISSN: 1864-564X
    Source: Alma/SFX Local Collection
    Source: © ProQuest LLC All rights reserved〈img src="https://exlibris-pub.s3.amazonaws.com/PQ_Logo.jpg" style="vertical-align:middle;margin-left:7px"〉
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  • 6
    Language: English
    In: ChemCatChem, 2018-04-24, Vol.10 (8), p.1739-1752
    Description: The development of silica‐supported molecular catalysts for tandem reactions is an important research direction of heterogeneous catalysis. Besides their significant merits in sustainable catalytic processes, numerous strategies have been utilized to construct silica‐supported molecular catalysts. Here, we emphasize tandem reactions and summarize the recent advances in sequential organic transformations. This paper is composed of four parts. The beginning part introduces silica as supports. The second part provides a large number of examples for the construction of non‐chiral molecular catalysts used for tandem reactions. The third part offers an outline for the construction of chiral molecular catalysts used for enantioselective tandem reactions. Finally, the perspectives for the further development of silica‐supported molecular catalysts for tandem reactions are addressed. In tandem: Tandem reactions catalyzed by silica‐supported molecular catalysts are of significant importance in green chemistry owing to their easy recyclability and environmentally benign fashion. This minireview focuses mainly on the constructions of silica‐supported molecular catalysts and summarizes the recent advances of sequential organic transformations through tandem reactions.
    Subject(s): tandem reaction ; asymmetric synthesis ; heterogeneous catalysis ; mesoporous material ; supported catalysis ; Heterogeneous catalysis ; Synthesis ; Catalysts ; Silica ; Organic compounds ; Catalysis ; Cascade chemical reactions ; Silicon dioxide
    ISSN: 1867-3880
    E-ISSN: 1867-3899
    Source: Academic Search Ultimate
    Source: Alma/SFX Local Collection
    Source: © ProQuest LLC All rights reserved〈img src="https://exlibris-pub.s3.amazonaws.com/PQ_Logo.jpg" style="vertical-align:middle;margin-left:7px"〉
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  • 7
    Language: English
    In: Sensors (Basel, Switzerland), 2021-02-22, Vol.21 (4), p.1514
    Description: Structural health monitoring is of great significance to ensure the safety of marine pipes, while powering the required monitoring sensors remains a problem because the ocean environment is not amenable to the traditional ways of providing an external power supply. However, mechanical energy due to the vortex-induced vibration of pipelines may be harvested to power those sensors, which is a convenient, economic and environmentally friendly way. We here exploit a contact-separation mode triboelectric nanogenerator (TENG) to create an efficient energy harvester to transform the mechanical energy of vibrating pipes into electrical energy. The TENG device is composed of a tribo-pair of dielectric material films that is connected to a mass-spring base to guarantee the contact-separation motions of the tribo-pair. Experimental tests are conducted to demonstrate the output performance and long-term durability of the TENG device by attaching it to a sample pipe. A theoretical model for the energy harvesting system is developed for predicting the electrical output performance of the device. It is established that the normalized output power depends only on two compound variables with all typical factors taken into consideration simultaneously. The simple scale law is useful to reveal the underlying mechanism of the device and can guideline the optimization of the device based on multi-parameters analyses. The results here may provide references for designing contact-mode TENG energy harvesting devices based on the vibration of marine pipes and similar structures.
    Subject(s): Index Medicus ; optimization design ; triboelectric nanogenerator ; marine pipelines ; mechanical energy harvesting ; scaling law
    ISSN: 1424-8220
    E-ISSN: 1424-8220
    Source: Academic Search Ultimate
    Source: PubMed Central
    Source: Directory of Open Access Journals
    Source: Alma/SFX Local Collection
    Source: © ProQuest LLC All rights reserved〈img src="https://exlibris-pub.s3.amazonaws.com/PQ_Logo.jpg" style="vertical-align:middle;margin-left:7px"〉
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  • 8
    Language: English
    In: The Journal of infectious diseases, 2013-03-01, Vol.207 (5), p.736-739
    Description: We investigated an outbreak of severe fever with thrombocytopenia syndrome (SFTS) that occurred during May and June 2010, to identify the mode of transmission. Contact with the index patient's blood was significantly associated with development of SFTS (P = .01, by the χ 2 test for linear trend); the frequency of contact with the index patient's blood increased the risk of SFTS in a dose-response manner (P = .03, by the χ 2 test for linear trend). We concluded that human-to-human transmission caused this cluster of cases.
    Subject(s): Thrombocytopenia ; Disease transmission ; MAJOR ARTICLES AND BRIEF REPORTS ; Sons ; Viral diseases ; Viruses ; Health care industry ; Epidemiology ; Blood ; Fever ; Diseases ; Fundamental and applied biological sciences. Psychology ; Miscellaneous ; Infectious diseases ; Microbiology ; Biological and medical sciences ; Medical sciences ; Virology ; Humans ; Middle Aged ; Molecular Sequence Data ; Male ; Sequence Analysis, DNA ; Sequence Homology, Nucleic Acid ; RNA, Viral - genetics ; Molecular Epidemiology ; Disease Outbreaks ; Blood - virology ; Bunyaviridae Infections - virology ; Phlebovirus - isolation & purification ; Bunyaviridae Infections - transmission ; Retrospective Studies ; Disease Transmission, Infectious ; Cohort Studies ; Blood-borne diseases ; Reports ; Pappataci fever ; Research ; Risk factors ; Methods ; Index Medicus ; Abridged Index Medicus
    ISSN: 0022-1899
    E-ISSN: 1537-6613
    Source: Oxford Journals 2017 Science Collection
    Source: Oxford Journals Full Collection 2013
    Source: Oxford Journals Full Collection 2012
    Source: Oxford Journals Full Collection 2015
    Source: Oxford Journals Full Collection 2014
    Source: Oxford Journals 2016 Current Collection
    Source: Oxford Journals A-Z Collection
    Source: Oxford Journals 2017 Current Collection
    Source: Oxford Journals 2017 Medicine Collection
    Source: JSTOR Early Journal Content
    Source: Oxford Journals 2016 Current and Archive A-Z Collection
    Source: © ProQuest LLC All rights reserved〈img src="https://exlibris-pub.s3.amazonaws.com/PQ_Logo.jpg" style="vertical-align:middle;margin-left:7px"〉
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  • 9
    Language: English
    In: International journal of advanced manufacturing technology, 2020-04-01, Vol.107 (9-10), p.3967-3979
    Description: To further improve the cutting performance of WC/Co tools in the dry cutting of Ti-6Al-4V alloy. Experiments in dry cutting titanium alloy were carried out using micro-textured YG8 tools under different cutting speeds and depths. Three kinds of YG8 tools with the rake face machined with line groove, sinusoidal groove, and rhombic groove were adopted as the micro-texture YG8 tools. The cutting force, friction coefficient of the tool-chip contact zone, chip morphology, tool wear, and surface quality of machined titanium alloy were analyzed. The results show that the micro-textured tools can effectively reduce the wear area on the rake face and flank face, improve the wear form on the rake face, reduce the occurrence of oxidation wear, and improve the surface quality of machined Ti-6Al-4V alloy. Therefore, micro-textured tools can effectively improve cutting performance and prolong tool life. The existence of micro-texture on the tool surface has a certain influence on the tool performance. The line groove-textured tool has the best effect, followed by the sinusoidal and rhombic groove-textured tools.
    Subject(s): Cutting tools ; Grooves ; Cutting speed ; Microtexture ; Titanium base alloys ; Tool life ; Titanium alloys ; Coefficient of friction ; Morphology ; Tool wear ; Surface properties ; Rapid prototyping ; Oxidation ; Machine tools ; Surface layers ; Cutting force ; Cutting parameters
    ISSN: 0268-3768
    E-ISSN: 1433-3015
    Source: Academic Search Ultimate
    Source: Alma/SFX Local Collection
    Source: ProQuest Central
    Source: © ProQuest LLC All rights reserved〈img src="https://exlibris-pub.s3.amazonaws.com/PQ_Logo.jpg" style="vertical-align:middle;margin-left:7px"〉
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  • 10
    Language: English
    In: Wireless networks, 2018-02, Vol.24 (2), p.611-625
    Description: Energy-harvesting wireless sensor network (WSN) is composed of unreliable wireless channels and resource-constrained nodes which are powered by solar panels and solar cells. Energy-harvesting WSNs can provide perpetual data service by harvesting energy from surrounding environments. Due to the random characteristics of harvested energy and unreliability of wireless channel, energy efficiency is one of the main challenging issues. In this paper, we are concerned with how to decide the energy used for data sensing and transmission adaptively to maximize network utility, and how to route all the collected data to the sink along energy-efficient paths to maximize the residual battery energy of nodes. To solve this problem, we first formulate a heuristic energy-efficient data sensing and routing problem. Then, unlike the most existing work that focuses on energy-efficient data sensing and energy-efficient routing respectively, energy-efficient data sensing and routing scheme (EEDSRS) in unreliable energy-harvesting wireless sensor network is developed. EEDSRS takes account of not only the energy-efficient data sensing but also the energy-efficient routing. EEDSRS is divided into three steps: (1) an adaptive exponentially weighted moving average algorithm to estimate link quality. (2) an distributed energetic-sustainable data sensing rate allocation algorithm to allocate the energy for data sensing and routing. According to the allocated energy, the optimal data sensing rate to maximize the network utility is obtained. (3) a geographic routing with unreliable link protocol to route all the collected data to the sink along energy-efficient paths. Finally, extensive simulations to evaluate the performance of the proposed EEDSRS are performed. The experimental results demonstrate that the proposed EEDSRS is very promising and efficient.
    Subject(s): Engineering ; Energy ; Communications Engineering, Networks ; Data sensing ; Routing ; IT in Business ; Computer Communication Networks ; Energy-harvesting sensor network ; Electrical Engineering ; Unreliable links ; Wireless sensor networks ; Electronic data processing ; Energy efficiency ; Algorithms ; Research ; Methods
    ISSN: 1022-0038
    E-ISSN: 1572-8196
    Source: Hellenic Academic Libraries Link
    Source: Alma/SFX Local Collection
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