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Tytuł:
Stochastic fractal based multiobjective fruit fly optimization
Autorzy:
Zuo, C.
Wu, L.
Zeng, Z. F.
Wei, H. L.
Powiązania:
https://bibliotekanauki.pl/articles/330026.pdf
Data publikacji:
2017
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
multiobjective optimization
fruit fly optimization algorithm
stochastic fractal
optymalizacja wielokryterialna
algorytm optymalizacji
fraktal stochastyczny
Opis:
The fruit fly optimization algorithm (FOA) is a global optimization algorithm inspired by the foraging behavior of a fruit fly swarm. In this study, a novel stochastic fractal model based fruit fly optimization algorithm is proposed for multiobjective optimization. A food source generating method based on a stochastic fractal with an adaptive parameter updating strategy is introduced to improve the convergence performance of the fruit fly optimization algorithm. To deal with multiobjective optimization problems, the Pareto domination concept is integrated into the selection process of fruit fly optimization and a novel multiobjective fruit fly optimization algorithm is then developed. Similarly to most of other multiobjective evolutionary algorithms (MOEAs), an external elitist archive is utilized to preserve the nondominated solutions found so far during the evolution, and a normalized nearest neighbor distance based density estimation strategy is adopted to keep the diversity of the external elitist archive. Eighteen benchmarks are used to test the performance of the stochastic fractal based multiobjective fruit fly optimization algorithm (SFMOFOA). Numerical results show that the SFMOFOA is able to well converge to the Pareto fronts of the test benchmarks with good distributions. Compared with four state-of-the-art methods, namely, the non-dominated sorting generic algorithm (NSGA-II), the strength Pareto evolutionary algorithm (SPEA2), multi-objective particle swarm optimization (MOPSO), and multiobjective self-adaptive differential evolution (MOSADE), the proposed SFMOFOA has better or competitive multiobjective optimization performance.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2017, 27, 2; 417-433
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Telomerase enhances osteogenic ifferentiation of sheep bone marrow mesenchymal stem cells (BMSCs) by up-regulating PI3K/Akt pathway in vitro
Autorzy:
Zhu, X.
Zhou, L.
Liu, Z.
Chen, X.
Wei, L.
Zhang, Z.
Liu, Y.
Zhu, Y.
Wang, Y.
Yang, X.
Han, Y.
Powiązania:
https://bibliotekanauki.pl/articles/2087304.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
bone marrow mesenchymal stem cells
telomerase
proliferation
osteogenic differentiation
PI3K/Akt signalling pathway
Źródło:
Polish Journal of Veterinary Sciences; 2020, 23, 3; 359-372
1505-1773
Pojawia się w:
Polish Journal of Veterinary Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparison of the Bending Resistance Properties of Carbon Fiber/Foam Sandwich Structural Composites with Different Laying Angles
Autorzy:
Zhu, Lvtao
Cao, Shengbin
Zhang, Xiaofeng
Shen, Wei
Zhu, Chengyan
Powiązania:
https://bibliotekanauki.pl/articles/2171959.pdf
Data publikacji:
2022
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:
sandwich structure
composite
carbon fibre
ply angle
three-point bending
Opis:
This research aimed to explore the influence of fiber laying angles on the bending resistance properties of carbon fiber/foam sandwich structural composites. Four kinds of composites with the following laying angles: [0°]8, [0°/45°/90°/-45°]s, [0°/90°]4 and [45°/-45°]4 were prepared and tested in three-point bending experiments. The results obtained showed that the bending resistance performance was the best when the laying angle was [0°]8, while it was the worst when the laying angle was [45°/-45°]4. Besides, it was found that the tensile performance was the best when the fibers were arranged in the 0° direction when the strength utilisation rate was the highest. In addition, by observing the failure morphologies of the composites, the delamination and foam cracking were found in the four groups of composites. In contrast, the phenomenon of significant fracture was found on composites with a laying angle of [45°/-45°]4 only, indicating it had a poor bending resistance performance.
Źródło:
Fibres & Textiles in Eastern Europe; 2022, 2 (151); 75--81
1230-3666
2300-7354
Pojawia się w:
Fibres & Textiles in Eastern Europe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Time-frequency Representation -enhanced Transfer Learning for Tool Condition Monitoring during milling of Inconel 718
Autorzy:
Zhou, Yuqing
Sun, Wei
Ye, Canyang
Peng, Bihui
Fang, Xu
Lin, Canyu
Wang, Gonghai
Kumar, Anil
Sun, Weifang
Powiązania:
https://bibliotekanauki.pl/articles/24200823.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
tool condition monitoring
time-frequency analysis
Markov Transition Field
transfer learning
Opis:
Accurate tool condition monitoring (TCM) is important for the development and upgrading of the manufacturing industry. Recently, machine-learning (ML) models have been widely used in the field of TCM with many favorable results. Nevertheless, in the actual industrial scenario, only a few samples are available for model training due to the cost of experiments, which significantly affects the performance of ML models. A time-series dimension expansion and transfer learning (TL) method is developed to boost the performance of TCM for small samples. First, a time-frequency Markov transition field (TFMTF) is proposed to encode the cutting force signal in the cutting process to two-dimensional images. Then, a modified TL network is established to learn and classify tool conditions under small samples. The performance of the proposed TFMTF-TL method is demonstrated by the benchmark PHM 2010 TCM dataset. The results show the proposed method effectively obtains superior classification accuracies for small samples and outperforms other four benchmark methods.
Źródło:
Eksploatacja i Niezawodność; 2023, 25, 2; art. no. 165926
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis and application of real-time compensation of positioning precision of the turntable with a harmonic function
Autorzy:
Zhou, Yi
Zhu, Weibin
Shu, Yi
Huang, Yao
Zou, Wei
Xue, Zi
Powiązania:
https://bibliotekanauki.pl/articles/2173885.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
harmonic function
positioning error
compensation
real-time
CORDIC
Opis:
In order to guarantee the accuracy of turntable angle measurement, a real-time compensation method for turntable positioning precision based on harmonic analysis is proposed in this paper. Firstly, the principle and feasibility of the real-time compensation method are analysed, and a detailed description of harmonic compensation is provided herein. Secondly, we analyse the relationships between the surface number of the polygon with the compensation order of the harmonic function and its corresponding compensation accuracy. The effects of the iterations number and the data width on calculation accuracy in the coordinate rotation digital computer (CORDIC) algorithm are analysed and the quantization models of the approximation error and rounding error of the CORDIC algorithm are established. Then, the calculation of the harmonic error function and real-time compensation processes are implemented on a field programmable gate array (FPGA) chip. The resource occupation and time delay of the phase angle calculation and the harmonic component calculation are discussed separately. Finally, the validity of the harmonic compensation method is proven through comparing the compensation effect with that of linear interpolation and the polynomial compensation method. The influences of the compensation order, the iterations number and the data width on the compensation results are demonstrated by simulation. A test platform with a laboratory-made FPGA circuit is built to evaluate the effect of real-time compensation with the harmonic function and the positioning error compensation can be performed within 760 ns. The results confirmed the effectiveness of the harmonic compensation method, revealing an improvement of the positioning precision from 54.21ʹʹ to 1.63ʹʹ, equivalent to 96.99% reduction in positioning error.
Źródło:
Metrology and Measurement Systems; 2022, 29, 3; 553--571
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Strategies in technology-enhanced language learning
Autorzy:
Zhou, Yalun
Wei, Michael
Powiązania:
https://bibliotekanauki.pl/articles/781045.pdf
Data publikacji:
2018
Wydawca:
Uniwersytet im. Adama Mickiewicza w Poznaniu
Tematy:
language learning strategies
self-regulated language learning
strategy instruction
strategy assessment
technology enhanced language learning
Opis:
The predominant context for strategy research over the last three decades has focused on language learning situated in a conventional classroom environment. Computer technology has brought about many changes in language learning and has become ecological and normalized rather than a supporting tool in the language classroom. Consequently, the landscape of language learning has been rapidly and largely changed with the normalization of technologies in people’s daily communication. The pervasive use of mobile technologies and easy access to online resources require that digital language learners understand and employ appropriate learning strategies for learning effectiveness and that their teachers are able and willing to teach these strategies as needed. This article provides an overview of the state-of-the-art research into technology-enhanced language learning strategies. The strategies under review include those for language learning skill areas, language subsystems, and self-regulated learning. At the end, we discuss the pressing issues that Digital Age language learning has posed to learners, teachers, and researchers and propose considerations for strategy research in digital realms.
Źródło:
Studies in Second Language Learning and Teaching; 2018, 8, 2; 471-495
2083-5205
2084-1965
Pojawia się w:
Studies in Second Language Learning and Teaching
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Praktyki w zakresie mikroinnowacji w przedsiębiorstwach chińskich – cechy, typy i determinanty
The Practices of Micro-Innovation in Chinese Enterprises: Traits, Types and Affecting Factors
Autorzy:
Zhou, Qing
Yang, Wei
Ma, Xiangyuan
Fang, Gang
Powiązania:
https://bibliotekanauki.pl/articles/1810847.pdf
Data publikacji:
2015-11-15
Wydawca:
Uniwersytet Warszawski. Wydawnictwo Naukowe Wydziału Zarządzania
Tematy:
micro-innovation
basic types
affecting factors
empirical research
mikroinnowacje
podstawowe typy
determinanty
badania empiryczne
Opis:
Mikroinnowacje, jako rodzaj innowacyjnego sposobu myślenia i proces innowacyjny, można podzielić na mikroinnowacje ciągłe, imitacyjne i niezależne. Podział ten oparty jest na wymiarach innowacyjności, zakłóceń rynku i powtarzalności w dziedzinie innowacji. Na podstawie badań teoretycznych i empirycznych w artykule dokonano analizy wpływu głównych determinant mikroinnowacji na kształtowanie ich typów. Determinanty te, do których należą zasoby produktywne, zasoby zarządcze i ograniczenia zewnętrzne, wywierają bardziej znaczący wpływ na mikroinnowacje imitacyjne, a jednocześnie wykazują mniejszą korelację z mikroinnowacjami niezależnymi i ciągłymi. Wdrażając mikroinnowacje, przedsiębiorstwa powinny wybrać odpowiedni typ lub odpowiednie kombinacje różnych typów mikroinnowacji na podstawie kompleksowej analizy wewnętrznych zasobów produktywnych, zasobów zarządczych oraz ograniczeń zewnętrznych.
Micro-innovation, a kind of innovative thinking and innovative manner, can be divided into continuous micro-innovation, imitating micro-innovation and independent micro-innovation based on the dimensions of innovativeness, market disruption and repetitiveness in the innovation domain. On the basis of theoretical and empirical research, this paper analyzes the impact of the main micro-innovation affecting factors on micro-innovation types. Affecting factors including productive resources, management resources and external restrictions have a more prominent impact on imitating micro-innovation, while having a lower correlation with independent micro-innovation and continuous micro-innovation. Enterprises should select an appropriate micro-innovation type or different type combinations according to the comprehensive analysis of enterprise internal productive resources, management resources and external restrictions when implementing micro-innovation.
Źródło:
Studia i Materiały; 2015, 2/2015 (19); 51-65
1733-9758
Pojawia się w:
Studia i Materiały
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental research on energy-size distribution model of coal particle bed comminution
Autorzy:
Zhou, Qiang
Guo, Qing
Pan, Yongtai
Zhu, Changyong
Wei, Yinghua
Powiązania:
https://bibliotekanauki.pl/articles/1845226.pdf
Data publikacji:
2020
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
coal
particle bed comminution
extended G-S distribution
JK size-dependent breakage model
mathematical modelling
Opis:
In order to accurately predict the particle size distribution (PSD) of coal particle bed comminution under different applied pressures, the tests of two kinds of coal with four size fractions under five different applied pressures were carried out by TAW-3000 hydraulic servo testing machine. The Gaudin-Schumann(G-S) distribution is extended by the fractal theory and the JK size-dependent breakage model is discussed. Two mathematical models for predicting PSD of crushing products in coal particle bed comminution are proposed. Results show that the relationship between the mass-specific energy and applied pressure is linear. Because of the protective effect of fine particles, the change of particle size modulus d0 in G-S distribution is not significant, while the distribution parameter α decreases logarithmically with the increase of mass-specific energy. With the decrease of size fraction, the crushability of coal particle bed decreases, and a master curve can be used to fit the comminution characteristics of coal particle bed with different size fractions. The extended G-S distribution model and the JK size-dependent breakage model have better fit the results of coal particle bed comminution. This research provides a useful reference for the mathematical modelling of coal particle bed comminution.
Źródło:
Physicochemical Problems of Mineral Processing; 2020, 56, 5; 772-783
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental research on the strength distribution of brittle spheres under compression
Autorzy:
Zhou, Qiang
Guo, Qing
Pan, Yongtai
Zhu, Changyong
Wei, Yinghua
Powiązania:
https://bibliotekanauki.pl/articles/1447969.pdf
Data publikacji:
2021
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
particle strength
breakage energy
crushing force
lognormal function
breakage probability
Opis:
The strength of a particle is one of the most crucial characteristics within a comminution process due to the mechanical stresses experienced by each particle. In this study, the K9 glass spheres and ceramic spheres were subjected to a breakage test. The test includes the breakage of up to 240 particles under compression to obtain the distribution of the breakage probability depending on the crushing force and breakage energy. The breakage test was conducted for five particle size fractions from each individual material. Thus obtained 10 crushing force distributions and corresponding 10 breakage energy distributions were fitted with lognormal distribution function. The parameters in the lognormal were analyzed including the effect of the material and particle size. Following this, the relationship between the crushing force and breakage energy was analyzed based on the Hertzian elastic contacts model and Tomas’s elastic-plastic contact model, respectively. Additionally, particle strength in terms of crushing force and breakage energy were compared and found to be size dependent. Finally, a simple transformation algorithm of distributions is developed. According to this algorithm the crushing force distribution can be transformed into breakage energy distribution and vice versa. The findings facilitate a better understanding of the particle strength distribution under compression and will help to improve the comminution process design, control and optimization.
Źródło:
Physicochemical Problems of Mineral Processing; 2021, 57, 2; 58-69
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Rare Earth Elements supply vs. clean energy technologies: new problems to be solve
Dostawy pierwiastków ziem rzadkich (REE) a czyste technologie energetyczne: nowe problemy do rozwiązania
Autorzy:
Zhou, B.
Li, Z.
Zhao, Y.
Zhang, C.
Wei, Y.
Powiązania:
https://bibliotekanauki.pl/articles/216173.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Instytut Gospodarki Surowcami Mineralnymi i Energią PAN
Tematy:
rare earth element
clean energy technology
supply chain
pierwiastki ziem rzadkich
czysta technologia energetyczna
łańcuch dostaw
Opis:
Rare earth elements (REEs) provide important properties to clean energy technologies such as wind turbine and hybrid electric vehicles. The global REE demand will grow rapidly during the global transformation toward a greener economy in the next decades. This high demand will require a steady supply chain in the long run. China has a monopoly of global REE production and extraction. The global REE supply chain runs the risk of disruption along with Chinese REE policy evolution. To overcome this supply chain vulnerability, new strategies and measures should be adopted to satisfy future REE supply/demand. There is a pressing need to explore REE deposits, develop efficient REE recycling techniques from end-of-life products, improve substitution technologies for REEs, and reduce the number of critical REEs used in devices. Such measures are facing significant challenges due to environmental factors and an unbalanced market, and overcoming them requires efforts from government and REE companies.
Pierwiastki ziem rzadkich (Rare Earths Elements) mają istotne znaczenie dla rozwoju czystych technologii energetycznych, takich jak turbiny wiatrowe czy pojazdy hybrydowe. Światowy popyt na REE będzie wzrastał w związku z globalną transformacją w kierunku bardziej czystej (ekologicznej) gospodarki w okresie najbliższych dziesięcioleci. Wysoki popyt wymagać będzie stabilnego łańcucha dostaw REE w dłuższej perspektywie. Chiny mają monopol w zakresie globalnej produkcji i wydobycia REE. Światowe dostawy REE obarczone są jednak ryzykiem zakłóceń wynikających z chińskiej polityki w tym zakresie. W związku z tym, powinny być przyjęte nowe środki i strategie w celu zaspokojenia przyszłego popytu/podaży na REE. Istnieje pilna konieczność: poszukiwania nowych złóż, opracowania skutecznych technik recyklingu z wycofanych z eksploatacji produktów, poprawy technologii z zastosowaniem substytutów REE oraz zmniejszenie liczby krytycznych pierwiastków ziem rzadkich w stosowanych urządzeniach. Działania te stanowią poważne wyzwanie ze względu na czynniki środowiskowe i niezrównoważony rynek (monopol podaży). Przezwyciężenie ich wymaga odpowiednich działań ze strony rządu i firm zajmujących się produkcją REE.
Źródło:
Gospodarka Surowcami Mineralnymi; 2016, 32, 4; 29-44
0860-0953
Pojawia się w:
Gospodarka Surowcami Mineralnymi
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On Implicit Heavy Subgraphs and Hamiltonicity of 2-Connected Graphs
Autorzy:
Zheng, Wei
Wideł, Wojciech
Wang, Ligong
Powiązania:
https://bibliotekanauki.pl/articles/32083821.pdf
Data publikacji:
2021-02-01
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
implicit degree
implicit o-heavy
implicit f-heavy
implicit c-heavy
Hamilton cycle
Opis:
A graph G of order n is implicit claw-heavy if in every induced copy of K1,3 in G there are two non-adjacent vertices with sum of their implicit degrees at least n. We study various implicit degree conditions (including, but not limiting to, Ore- and Fan-type conditions) imposing of which on specific induced subgraphs of a 2-connected implicit claw-heavy graph ensures its Hamiltonicity. In particular, we improve a recent result of [X. Huang, Implicit degree condition for Hamiltonicity of 2-heavy graphs, Discrete Appl. Math. 219 (2017) 126–131] and complete the characterizations of pairs of o-heavy and f-heavy subgraphs for Hamiltonicity of 2-connected graphs.
Źródło:
Discussiones Mathematicae Graph Theory; 2021, 41, 1; 167-181
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Toughness, Forbidden Subgraphs, and Hamilton-Connected Graphs
Autorzy:
Zheng, Wei
Broersma, Hajo
Wang, Ligong
Powiązania:
https://bibliotekanauki.pl/articles/32361744.pdf
Data publikacji:
2022-02-01
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
toughness
forbidden subgraph
Hamilton-connected graph
Hamiltonicity
Opis:
A graph G is called Hamilton-connected if for every pair of distinct vertices {u, v} of G there exists a Hamilton path in G that connects u and v. A graph G is said to be t-tough if t·ω(G − X) ≤ |X| for all X ⊆ V (G) with ω(G − X) > 1. The toughness of G, denoted τ (G), is the maximum value of t such that G is t-tough (taking τ (Kn) = ∞ for all n ≥ 1). It is known that a Hamilton-connected graph G has toughness τ (G) > 1, but that the reverse statement does not hold in general. In this paper, we investigate all possible forbidden subgraphs H such that every H-free graph G with τ (G) > 1 is Hamilton-connected. We find that the results are completely analogous to the Hamiltonian case: every graph H such that any 1-tough H-free graph is Hamiltonian also ensures that every H-free graph with toughness larger than one is Hamilton-connected. And similarly, there is no other forbidden subgraph having this property, except possibly for the graph K1 ∪ P4 itself. We leave this as an open case.
Źródło:
Discussiones Mathematicae Graph Theory; 2022, 42, 1; 187-196
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Assessing the effectiveness of training programme on the competency of medical staffs in public health emergency
Autorzy:
Zhao, Yuhan
Wei, Chenming
Ni, Liezong
Zhang, Jinghua
Yin, Xunbao
Sun, Hongwei
Powiązania:
https://bibliotekanauki.pl/articles/2188853.pdf
Data publikacji:
2023
Wydawca:
Instytut Medycyny Pracy im. prof. dra Jerzego Nofera w Łodzi
Tematy:
competency
system professional training
public health emergency
self-designed questionnaire
medical staffs
training
Opis:
Background The competencies of medical staff in the public health emergency system and evaluated the effects of system-based professional training were investigated. Material and Methods A competency model for individuals in a public health emergency management system was developed, which contained 33 items with 5 domains. A competency-based intervention was performed. A total of 68 participants from 4 health emergency teams in Xinjiang, China were recruited and randomly divided into 2 groups: the intervention (N = 38) and control groups (N = 30). Participants in the intervention group received competency-based training, while those in the control group received no training. All participants responded to the COVID-19 activities. The competencies of medical staff in the 5 domains were then analyzed in the pre-intervention, post-first training, and post-COVID-19 intervention using a self-designed questionnaire. Results Participants’ competencies were at the middle level at baseline. After the first training, competencies in the 5 domains significantly improved in the intervention group; in the control group, there was a significant increase in professional quality compared in the pre-training. After the response to COVID-19, the mean scores of competencies in the 5 domains significantly increased in both the intervention and control groups compared with those in the post-first training. Psychological resilience scores were higher in the intervention group than in the control group, whereas no significant differences in competencies were found in other domains. Conclusions Competency-based interventions provided practice and showed a positive effect on improving the competencies of medical staff in public health teams. Med Pr. 2023;74(1)
Źródło:
Medycyna Pracy; 2023, 74, 1; 19-26
0465-5893
2353-1339
Pojawia się w:
Medycyna Pracy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Flotation separation of quartz from phosphorite using an imidazole ionic liquid collector and its adsorption mechanism
Autorzy:
Zhao, Yuanyuan
Xu, Wei
Mei, Guangjun
Yu, Mingming
Yang, Siyuan
He, Zhan
Powiązania:
https://bibliotekanauki.pl/articles/2146857.pdf
Data publikacji:
2022
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
reverse flotation
imidazole ionic liquid
desilication
phosphorite
quartz
Opis:
In this study, an imidazole ionic liquid (dodecyl-tri-methylimidazolium chloride) was employed as a collector to separate quartz from phosphorite. The micro-flotation experiments of a single mineral found that it had selective collecting ability for quartz than phosphorite. Mixed mineral flotation experiments confirmed that efficient separation results could be obtained using the imidazole ionic liquid as the collector. A concentrate with a 31.44% grade of phosphorite could be obtained with a 0.285 kg/Mg collector dosage at neutral pH, which was much better than the traditional collector dodecylamine. The adsorption mechanism of the imidazole ionic liquid on the surface of phosphorite and quartz was investigated by contact angle and zeta potential measurements, Fourier transform infrared and X-ray photoelectron spectroscopy analyses. These results showed that the adsorption of imidazole ionic liquid at the quartz surface was stronger than that of phosphorite, and the collector adsorbability difference between quartz and phosphorite resulted in the efficient flotation separation. Consequently, the dodecyl-tri-methylimidazolium chloride salt is an effective collector for reverse flotation of quartz from phosphorite.
Źródło:
Physicochemical Problems of Mineral Processing; 2022, 58, 1; 159--168
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research on the Critical Sizes for Detonation of Cube-shaped Transfer Charges
Autorzy:
Zhao, Xiang-run
Jin, Shi-xin
Huang, Jin-hong
Li, Chao-zhen
Yan, Li-wei
Powiązania:
https://bibliotekanauki.pl/articles/358353.pdf
Data publikacji:
2019
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
explosive train
transfer charge
shock wave sensitivity
minimum safe separation distance
Opis:
In order to obtain the minimum size, thickness and safe separation distance, for the cube-shaped transfer charges used in MEMS (micro-electromechanical system) explosive trains, an explosive train using a JO-9C(III) cube-shaped transfer charge was designed for experimental research. Detonation transfer experiments and detonation interruption experiments were conducted in turn. In initial experiments, the electric detonators were all in the armed position, but different thicknesses of the cube-shaped transfer charges were used. In the later experiments, the thickness of the transfer charges were unchanged, but the separation distances were different. The detonation path of the transfer charge under unsafe conditions was analyzed using the shock wave attenuation law. The results showed that the minimum thickness ranged from 0.2 mm to 0.4 mm, the minimum safe separation distance ranged from 0.4 mm to 0.6 mm; and the cube-shaped transfer charge is detonated by a shock wave from a steel gap rather than air clearance when the safe separation distance is less than the minimum threshold. The thickness design value of the cube-shaped transfer charge (JO-9C(III)) should not be less than 0.6 mm, and the safe separation distance design value of the MEMS explosive train should not be less than 1 mm.
Źródło:
Central European Journal of Energetic Materials; 2019, 16, 1; 91-104
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł

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