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Tytuł:
“The Gateway to Europe”. The Discourse on Poland in the Chinese Press (2015-2020)
Ворота в Европу. Дискурс о Польше в китайской прессе (2015-2020)
Autorzy:
Yang, Cao
Płaneta, Paweł
Powiązania:
https://bibliotekanauki.pl/articles/1930287.pdf
Data publikacji:
2021-09-30
Wydawca:
Wydawnictwo Adam Marszałek
Tematy:
press image of Poland
discourse
foreign news
content analysis
Chinese press
образ Польши в прессе
дискурс
зарубежные новости
контентанализ
китайская пресса
Opis:
The aim of the article is to present the results of the survey on the structure of the discourse on Poland present in the content of various Chinese newspapers and magazines. In the first part, we provide an overview of the history, characteristic and development trends of the Chinese newspaper market. In order to construct the collection of messages about Poland and Poles, a query was carried out in 172 journalistic materials published in 2015-2020. The first step of analysis performed in this research was the lexical analysis of the Chinese print media gathered in the text corpus of app. 160 thous. words. Additionally, the authors of the article used text mining analytics software to extract the main concepts. The next phase of the survey was the computer assisted content analysis. For the research purposes 150 categories dictionaries were created. Those dictionaries consisted of the set of words gathered on the same semantic basis. The unit of the analysis in this phase of the research was a single paragraph (N=2465 units) and the results of this analysis were the hierarchy and key-ness of collective symbols, themes, actors and places present in the press discourse on Poland. In the last part of the research—as a result of factor analysis—the structure of the discourse on Poland in the Chinese press was reduced to 9 strongest factors determining which different (detailed) categories have the tendency to co-occur and that is why they create easily distinguishable configurations.
Цель статьи - представить результаты исследования структуры дискурса о Польше, присутствующего в содержании различных китайских газет и журналов. В первой части сделан обзор истории, характеристик и тенденций развития китайского газетного рынка. Для подборки сообщений о Польше и поляках был проведен анализ 172 публицистических материалов, опубликованных в 2015-2020 годах. Первым шагом в данном исследовании стал лексический анализ китайских печатных СМИ, собранных в текстовом корпусе приложения, содержащего 200 000 слов. Кроме того, для анализа текстов авторы статьи использовали программное обеспечение для извлечения основных концепций. Следующим этапом исследования стал компьютерный контент-анализ. Для исследовательских целей создано 150 категорий словарей. Эти словари состояли из набора слов, собранных на одной семантической основе. Единицей анализа на этом этапе исследования был отдельный абзац (N = 2465 единиц), а результатом - иерархия и значимость коллективных символов, тем, актеров и мест, присутствующих в печатном дискурсе относительно Польши. В последней части исследования - при помощи факторного анализа - структура дискурса о Польше в китайской прессе была сведена к 9 сильнейшим факторам, определяющим, какие различные (детализированные) категории имеют тенденцию к совместному появлению и именно поэтому создают легко различимую конфигурацию.
Źródło:
Nowa Polityka Wschodnia; 2021, 3(30); 98-132
2084-3291
Pojawia się w:
Nowa Polityka Wschodnia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
论中国在欧盟标准方面的环境政策 / China’s environmental policy in terms of European Union standards
Chinas environmental policy in terms of European Union standards
论中国在欧盟标准方面的环境政策
Autorzy:
Tkaczyński, Jan Wiktor
Gacek, Łukasz
Jaworski, Wojciech
Chmielowski, Jan
Yang, Cao
Junjie, Liu
Powiązania:
https://bibliotekanauki.pl/books/18104622.pdf
Data publikacji:
2021-10-29
Wydawca:
Uniwersytet Jagielloński. Wydawnictwo Uniwersytetu Jagiellońskiego
Opis:
Pozostaje poza dyskusją, że tak w interesie Chin jak i Unii Europejskiej leży promowanie rozwoju niskoemisyjnego poprzez upowszechnianie czystych i odnawialnych źródeł energii, ponieważ prowadzi to do wzrostu stopnia ochrony środowiska naturalnego. Wyczerpywanie się bowiem zasobów paliw kopalnych i towarzyszące temu zmiany w światowej strukturze energetycznej sprawiają, że zarówno Europa jak i Chiny stają się nie tylko współzawodnikami w światowym wyścigu gospodarczym, ale i nolens volens partnerami. Tę tak tworzoną z pragmatycznych względów wspólnotę charakteryzuje z jednej strony potrzeba podejmowania działań zmierzających do ograniczania zużycia paliw kopalnych, z drugiej zaś chęć zminimalizowania negatywnego wpływu na środowisko naturalne ich wykorzystywania. Stąd współpraca ta, niełatwa przecież z różnych względów, to nie tylko dążenie do wymiany potrzebnych informacji, ale również próba ustalenia standardów, według których ma być ona realizowana.
It is beyond dispute that both China and the European Union stand to gain from promoting low-carbon development through the dissemination of clean and renewable energy sources, as this inevitably leads to increased environmental protection. The depletion of fossil fuel resources and the accompanying changes in the global energy mix make Europe and China not only competitors in the global economic race, but also nolens volens partners. Their pragmatic partnership is characterized, on the one hand, by the need to take action to reduce the consumption of fossil fuels and, on the other, by the desire to minimize the negative environmental impact of their use. Hence, the existing and emerging cooperation between the two actors, while challenging for a number of reasons, is not only an attempt to set up channels to exchange vital information, but also an exercise in setting the standards under which further cooperation will be forged.
Dostawca treści:
Biblioteka Nauki
Książka
Tytuł:
Analiza motywacji, problemów i potrzeb chińskich młodszych nauczycieli języka polskiego jako obcego
Analysis of motivation, problems, and needs of Chinese junior teachers of Polish as a foreign language
Autorzy:
Wang, Jing
Zhang, Huiling
Cao, Yang
Powiązania:
https://bibliotekanauki.pl/articles/31339962.pdf
Data publikacji:
2022
Wydawca:
Uniwersytet Gdański. Wydawnictwo Uniwersytetu Gdańskiego
Opis:
With the dynamic development of Chinese Polish Studies since 2018, there has been a growing demand for teachers of Polish as a foreign language who are native Chinese speakers in the labour market of the People’s Republic of China. Nowadays, almost every Polish language centre at a university has its own teaching staff. Many of them are not only quite modest in terms of staff numbers, but also very young in terms of the age and experience of the teachers. Today, both Polish and Chinese language literature still lacks in-depth research on this specific group of glottodidactics. Therefore, the present study aims at getting to know Chinese junior teachers of Polish as a foreign language working at universities, and to gain knowledge about their motivation for their profession, problems and needs at work. From the questionnaire survey of 23 purposively selected respondents, it can be concluded that the greatest motivation of the respondents was related to students and interests in research and/or teaching. The problems they encountered at work were related to insufficient skills, lack of materials and those caused by the work environment. They are most in need of improved teaching methods and techniques, more and better teaching materials and help from masters in this field.
Źródło:
Gdańskie Studia Azji Wschodniej; 2022, 21; 129-145
2353-8724
Pojawia się w:
Gdańskie Studia Azji Wschodniej
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Stability and dissipativity analysis for neutral type stochastic Markovian jump static neural networks with time delays
Autorzy:
Cao, Yang
Samidurai, R.
Sriraman, R.
Powiązania:
https://bibliotekanauki.pl/articles/91527.pdf
Data publikacji:
2019
Wydawca:
Społeczna Akademia Nauk w Łodzi. Polskie Towarzystwo Sieci Neuronowych
Tematy:
static neural networks
dissipativity analysis
Markovian jump
time-varying delays
Opis:
This paper studies the global asymptotic stability and dissipativity problem for a class of neutral type stochastic Markovian Jump Static Neural Networks (NTSMJSNNs) with time-varying delays. By constructing an appropriate Lyapunov-Krasovskii Functional (LKF) with some augmented delay-dependent terms and by using integral inequalities to bound the derivative of the integral terms, some new sufficient conditions have been obtained, which ensure that the global asymptotic stability in the mean square. The results obtained in this paper are expressed in terms of Strict Linear Matrix Inequalities (LMIs), whose feasible solutions can be verified by effective MATLAB LMI control toolbox. Finally, examples and simulations are given to show the validity and advantages of the proposed results.
Źródło:
Journal of Artificial Intelligence and Soft Computing Research; 2019, 9, 3; 189-204
2083-2567
2449-6499
Pojawia się w:
Journal of Artificial Intelligence and Soft Computing Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The demand analysis of oceanic T-S-V 3D reconstruction on wide-swath SSH data features based on ROMS and 4DVAR
Autorzy:
Zhou, C.
Zhang, J.
Yang, J.
Cao, L.
Powiązania:
https://bibliotekanauki.pl/articles/2079186.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
sea surface
anomaly
wide-swath altimeter
3D reconstruction
accuracy
Regional Ocean Modelling System
demand analysis
Opis:
Future wide-swath altimetry missions will provide high-resolution information about ocean surface elevation, and facilitate the characterization of meso- and sub-mesoscale ocean activities. In this study, the demand analysis of three-dimensional (3D) oceanic state reconstruction on wide-swath SSH data features was evaluated using a data assimilation strategy. Three groups of experiments were performed to determine if the wide-swath altimetry observations would improve the three-dimensional (3D) field estimates of ocean temperature-salinity-velocity (T-S-V), and to evaluate how the spatial and temporal resolution and accuracy of the wide-swath altimetry observations affected the ocean state estimation. The Regional Ocean Modeling System and the four-dimensional variational data assimilation method were used in the experiments, with numerical simulation for the Taiwan region at a resolution of 1/10° as the example. The sensitivity of the 3D ocean state construction to the wide-swath altimetry measurements was also investigated. The results showed that the wide-swath sea surface height (SSH) measurements would have an overall positive impact on the 3D T-S-V field and that the positive effect would increase as the resolution and accuracy of the observations increased, but the net benefits would gradually decrease. Among the three examined features of the wide-swath altimetry observations, the temporal resolution had the most influence on the 3D ocean state analysis.
Źródło:
Oceanologia; 2020, 62, 3; 309-325
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ultrafiltration treatment of wastewater contained heavy metals complexed with palygorskite
Autorzy:
Ren, Jun
Cao, Tiany
Yang, Xin
Tao, Ling
Powiązania:
https://bibliotekanauki.pl/articles/778555.pdf
Data publikacji:
2020
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
palygorskite
heavy metals
ultrafiltration
complexation
pH
ionic strength
Opis:
Palygorskite was applied in complexation-ultrafiltration treatment of heavy metals in wastewater under different pH and ionic strength. The results indicated that the rejection of heavy metals increased significantly with pH value, and decreased slightly with an increase of ionic strength of Na+ and Cl-. A certain concentration of NaCl significantly reduced the rejection rate of Cu2+. The rejection of Cu2+, Zn2+ and Cd2+ could reach over 86.8%, 93.6% and 93.7% at pH of 7 and 0.1 mol/L NaCl. The rejection of heavy metals was severely affected by low molecular weight competing complexing agents and the effect of sodium tartrate was greater than triethanolamine. In the presence of sodium tartrate, the rejection of Cu2+, Zn2+ and Cd2+ could arrive over 81.4%, 57.6% and 60.5% at pH of 7 in 20 min. Palygorskite was offered a potential complexing agent for the removal of heavy metals in wastewater at the complexation-ultrafiltration process.
Źródło:
Polish Journal of Chemical Technology; 2020, 22, 4; 1-9
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
New event based H∞ state estimation for discrete-time recurrent delayed semi-markov jump neural networks via a novel summation inequality
Autorzy:
Cao, Yang
Maheswari, K.
Dharan, S.
Sivaranjani, K.
Powiązania:
https://bibliotekanauki.pl/articles/2147136.pdf
Data publikacji:
2022
Wydawca:
Społeczna Akademia Nauk w Łodzi. Polskie Towarzystwo Sieci Neuronowych
Tematy:
discrete-time neural networks
mixed time delays
asymptotic stability
eventtriggered control
Opis:
This paper investigates the event-based state estimation for discrete-time recurrent delayed semi-Markovian neural networks. An event-triggering protocol is introduced to find measurement output with a specific triggering condition so as to lower the burden of the data communication. A novel summation inequality is established for the existence of asymptotic stability of the estimation error system. The problem addressed here is to construct an H∞ state estimation that guarantees the asymptotic stability with the novel summation inequality, characterized by event-triggered transmission. By the Lyapunov functional technique, the explicit expressions for the gain are established. Finally, two examples are exploited numerically to illustrate the usefulness of the new methodology.
Źródło:
Journal of Artificial Intelligence and Soft Computing Research; 2022, 12, 3; 207--227
2083-2567
2449-6499
Pojawia się w:
Journal of Artificial Intelligence and Soft Computing Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical Investigation of the Propagation Characteristics of Surface Transverse Wave Considering Various Quartz Substrate and Electrode Configurations
Autorzy:
Jiang, Chao
Cao, Xiaoli
Yang, Feng
Liu, Zejun
Powiązania:
https://bibliotekanauki.pl/articles/31339822.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
surface transverse wave
STW
interdigital transducer
IDT
finite element analysis
FEA
quartz
Opis:
Featured with a higher velocity, increased power handling capability, and better aging behavior, surface transverse wave (STW) shows more promising prospects than Rayleigh wave nowadays in various sensing applications. The need to design, optimize, and fabricate the related devices motivates the development of modeling and simulation. For this reason, a three-dimensional (3D) finite element (FE) simulation of STW on quartz, considering the crystal cut angle and the electrode effects, is presented in this study. Firstly, we investigated the effects of quartz’s cut angle on the generated waves. Here, the polarized displacements were analyzed to distinguish the wave modes. Secondly, the investigations of the electrode effects on the polarized displacement, phase velocity, and electromechanical coupling factor (K2) were carried out, for which different material and thickness configurations for the electrodes were considered. Thirdly, to examine the excitation conditions of the generated waves, the admittance responses were inspected. The results showed that not only the crystal cut angle but also the density and the acoustic impedance of the interdigital transducer (IDT) material have a strong influence on the excited waves. This article is the first to analyze STWs considering quartz’s cut angle and electrode effect through a 3D FE model. It could provide a helpful and easy way to design, optimize, and fabricate the related surface acoustic wave devices.
Źródło:
Archives of Acoustics; 2023, 48, 3; 403-412
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A first-principle study of the effect of Fe/Al impurity defects on the surface wettability of dolomite
Autorzy:
Chen, Hong
Ao, Xianquan
Cao, Yang
Li, Cuiqin
Jiang, Chunyan
Powiązania:
https://bibliotekanauki.pl/articles/2146916.pdf
Data publikacji:
2022
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
density functional theory
phosphate rock flotation
dolomite
surface wettability
density of states
Opis:
The presence of Fe and Al atoms in large quantities in phosphate ores can significantly affect the surface properties of the minerals during flotation. In this study, the effects of Fe/Al impurities on the adsorption of H2O molecules on dolomite, including the density of states (DOS), Mulliken bond group values, and charge groups, were investigated and the adsorption energy was analyzed using density functional theory. The results show that the adsorption of H2O molecules on perfect and Fe/Al-substituted dolomites is weak chemisorption, and the Fe and Al impurities weaken and enhance the adsorption capacity of H2O molecules, respectively. Therefore, the hydrophilicity of the dolomite surface increases in the following order: Fe-substituted dolomite < perfect dolomite < Al-substituted dolomite. The Mulliken charge and bond group analysis shows that the adsorption of H2O molecules on dolomite is primarily through the interaction between Ow and Ca atoms, where the d orbitals of Ca atoms provide charges for Ow atoms to form ionic bonds, which related to the poor electronegativity of Ca atoms and their weak valence electron binding ability. The DOS analysis shows that, during the adsorption of H2O molecules on dolomite, Mg and Al atoms have less influence on the dolomite surface, whereas Fe and Ca atoms undergo competitive adsorption, which inhibits the interaction between Ca atoms and H2O molecules on the dolomite surface.
Źródło:
Physicochemical Problems of Mineral Processing; 2022, 58, 4; art. no. 150702
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental and numerical investigations on dynamic tensile behavior of a ZrB2-SiC ceramic
Autorzy:
He, R.
Cao, J.
Yang, K.
Wang, L.
Kong, D.
Powiązania:
https://bibliotekanauki.pl/articles/38695710.pdf
Data publikacji:
2023
Wydawca:
Instytut Podstawowych Problemów Techniki PAN
Tematy:
ZrB2-SiC ceramic
dynamic tensile properties
fracture pattern
strain rate
peridynamic model
Opis:
The dynamic tensile behavior of a ZrB2-SiC ceramic was investigated via split Hopkinson pressure bar tests and a bond-based peridynamic model. The experimental results showed that the peak dynamic splitting tensile stress increased linearly with the strain rate. The dynamic tensile stress history and fracture pattern exhibited a significant strain-rate dependence. In simulation, the strain-rate dependent on the critical energy release rate was introduced to predict the dynamic tensile behavior of the ZrB2-SiC ceramic. The numerical results were in good agreement with the experimental results, verifying the applicability of the peridynamic model. The maximum error of the peak dynamic splitting tensile stress between the experimental and numerical results was no greater than 6%. Moreover, the effect of the strain rate on the fracture patterns of the ZrB2-SiC ceramic composite can be well predicted by the peridynamics method. The ZrB2-SiC composite specimen split into two large fragments with additional small fragments under dynamic splitting tension. With the increase of strain rate, the main crack propagation and branching led to a larger fracture region in the middle of the specimen.
Źródło:
Archives of Mechanics; 2023, 75, 1-2; 53-73
0373-2029
Pojawia się w:
Archives of Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Improvement of phytoremediation potential of Indian mustard by sulfur treatment of cadmium-contaminated soil
Autorzy:
Sun, Kaining
Yang, Ning
Cao, Yaru
Wang, Kean
Li, Xuhua
Powiązania:
https://bibliotekanauki.pl/articles/2032914.pdf
Data publikacji:
2021
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
Indian mustard
soil
Cd
phytoremediation
Brassica juncea
gorczyca indyjska
gleba
fitoremediacja
Opis:
The phytoremediation potential of Indian mustard (Brassica juncea) on the cadmium-contaminated soil was investigated under the treatment of sulfur (15, 30 and 60 g/kg soil). The effects of the sulfur treatment were evaluated by measuring the biomass and root vitality of the plants, enzymatic activities, and the content of malondialdehyde and Cd. The results show that the biomass and root vitality of the plants were significantly increased, and the activities of superoxide dismutase and catalase were improved when the soil was treated with 30 g sulfur /kg soil, while the activities of peroxidase and malondialdehyde were decreased. The total Cd in the plants treated with 15 g/kg soil was 2.8 times higher than that in the control plants. In summary, the results indicate that the addition of sulfur could promote the growth of Indian mustard and promote the uptake of Cd. As such, the treatment of cadmium-contaminated soil with sulfur can be used as a strategy for the removal of cadmium contamination by improving the phytoremediation potential of Indian mustard.
Źródło:
Environment Protection Engineering; 2021, 47, 2; 5-15
0324-8828
Pojawia się w:
Environment Protection Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effects of benzo(a)pyrene exposure on the ATPase activity and calcium concentration in the hippocampus of neonatal rats
Autorzy:
Yang, Kai
Chen, Chengzhi
Cheng, Shuqun
Cao, Xianqing
Tu, Baijie
Powiązania:
https://bibliotekanauki.pl/articles/2161850.pdf
Data publikacji:
2017-03-30
Wydawca:
Instytut Medycyny Pracy im. prof. dra Jerzego Nofera w Łodzi
Tematy:
hippocampus
neurodevelopment
ATPase activity
Ca2+ concentration
neonatal rats
Benzo(a)pyrene
Opis:
Objectives To investigate whether postnatal benzo(a)pyrene (B(a)P) exposure caused the impairments on the process of neurodevelopment and the alteration in the calcium medium in the neonatal rats. Material and Methods Eighty neonatal Sprague Dawley (SD) rats were randomly divided into 5 groups (untreated control group, vehicle group, 0.02 mg/kg, 0.2 mg/kg and 2 mg/kg B(a)P-exposed group). Rats were treated with B(a)P by the intragastric administration from postnatal day (PND) 4 to 25. Morris water maze (MWM) was employed to observe the spatial memory of rats. The activity of calcium adenosine triphosphatase (Ca2+-ATPase), sodium-potassium adenosine triphosphatase (Na+-K+-ATPase) and calcium-magnesium adenosine triphosphatase (Ca2+-Mg2+-ATPase) in the hippocampus were detected by commercial kits. Fura-2 pentakis(acetoxymethyl) (Fura-2/AM) probe and reactive oxygen species (ROS) reagent kit were used for measuring the concentration of Ca2+ and ROS in the hippocampus synapse, respectively. Results Rats exposed to B(a)P resulted in the deficits in the spatial memory manifested by the increased escape latency and decreased number of crossing platform and time spent in target quadrant in comparison with the control groups. Benzo(a)pyrene exposure caused the significant decrease in the ATPase activity in the hippocampus and caused Ca2+ overload in the synaptic, besides, the ROS concentration increased significantly which may further induce neurobehavioral impairment of the neonatal rats. Conclusions Our findings suggest that postnatal B(a)P exposure may cause the neurobehavioral impairments in the neonatal rats, which were mediated by the decreased ATPase activity and elevated Ca2+ concentration. Int J Occup Med Environ Health 2017;30(2):203–211
Źródło:
International Journal of Occupational Medicine and Environmental Health; 2017, 30, 2; 203-211
1232-1087
1896-494X
Pojawia się w:
International Journal of Occupational Medicine and Environmental Health
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application cumulative tensile explosions for roof cutting in Chinese underground coal mines
Autorzy:
Yang, Jun
Liu, Binhui
Bian, Wenhui
Chen, Kuikui
Wang, Hongyu
Cao, Chen
Powiązania:
https://bibliotekanauki.pl/articles/2073869.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
roboty strzałowe
wysadzanie skał
kopalnia
cumulative blast
bilateral cumulative tensile explosion
roof cutting and pressure relief technology
gob-side entry retaining
Opis:
Cumulative blasts are an important controlled blasting method used to control the propagation of cracks in the predetermined direction. However, traditional cumulative blasts are associated with long processing times and poor blasting effects. A simple blasting technology called bilateral cumulative tensile explosion (BCTE) is proposed in this paper. There are two application types where BCTE is used. The first application is used to control the stability of high-stress roadways in both Wangzhuang mine 6208 tailgate and Hongqinghe mine 3-1103 tailgate. The second application is used to replace the backfill body in gob-side entry retaining (GER) in Chengjiao mine 21404 panel, Jinfeng mine 011810 panel and Zhongxing mine 1200 panel. The first application type reveals that BCTE can significantly reduce the deformation of the surrounding rock and reduce the associated maintenance cost of the roadways. Whereas the second application type, the roadway deformations are smaller, the process is simpler, and the production costs are lower, which further promotes GER and is of significance towards conserving resources.
Źródło:
Archives of Mining Sciences; 2021, 66, 3; 421--435
0860-7001
Pojawia się w:
Archives of Mining Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Chemical Information of Chitosan-Based Complex Extracted from Coincidence Doppler Broadening Spectra
Autorzy:
Cao, Xingzhong
Xia, Rui
Yang, Jing
Zeng, Minfeng
Wang, Baoyi
Yu, Runsheng
Wei, Long
Powiązania:
https://bibliotekanauki.pl/articles/1033908.pdf
Data publikacji:
2017-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.70.Bj
64.70.km
82.30.Gg
Opis:
In recent years, coincidence Doppler broadening (CDB) of annihilation radiation measurement on polymeric system has been attracting special attention because of its unique elemental sensitivities in comparison to the traditional Doppler broadening measurement. In the present study, chitosan-Fe₃O₄ nanocomposite (CS-Fe₃O₄) and copper-chitosan (Cu-CS) complexes were prepared through a simple casting method from aqueous solution. The inclusion of Fe₃O₄ nanoparticles in the chitosan matrix is confirmed by X-ray diffraction. In order to obtain data about atomic composition of the annihilation site in the CS composites, CDB measurements were carried out. The normalized CDB ratio curve, which is related to the ratio between the momentum density distribution for the studied samples and pure CS, was displayed to illustrate the variation of ion cores of different elements present in the chitosan matrix. Our result confirms a contribution of active group available in chitosan molecules to the features in the high-momentum region of the CDB ratio curve. The findings show that the local chemical environment of the annihilation site in chitosan-based complexes could be estimated by such positron annihilation spectroscopic investigation.
Źródło:
Acta Physica Polonica A; 2017, 132, 5; 1535-1537
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Natural filling and systematic roof control technology for gob-side entry retaining in steep coal seams
Naturalne podsadzanie stropu i metoda systemowego prowadzenia stropu przy utrzymaniu chodników przewozowych od strony zrobów w nachylonych pokładach węgla
Autorzy:
Yang, H.
Cao, S.
Zhou, G.
Zhao, Y.
Li, G.
Li, Y.
Fan, Y.
Powiązania:
https://bibliotekanauki.pl/articles/220162.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
utrzymanie chodnika przewozowego
nachylone pokłady węgla
naturalne podsadzanie
projekt systemowy
gob-side entry retaining
steep coal seams
natural filling
systematic project
Opis:
The technology for gob-side entry retaining in steep coal seams is still in the development stage. The analysis results of the caving structure of main roof, low influence of gateway’s stability because of long filling distance and weak dynamic effect of the gateway, and the low stress redistribution environment indicate that using this technology in steep coal seams has significant advantages. Moreover, to reinforce the waste rock and the soft floor and to better guard against the impact of the waste rock during natural filling, a rock blocking device and grouting reinforcement method were invented, and theoretical calculations result show that the blocking device has high safety factor. In addition, we also developed a set of hydraulic support devices for use in the strengthening support zone. Furthermore, because the retaining gateway was a systematic project, the selection of the size and shape of the gateway cross section and its support method during the initial driving stage is a key step. Thus, first, a section the size of bottom width and roof height of a new gateway was determined to meet any related requirements. Then, according to the cross sections of 75 statistical gateways and the support technique, it chosen a trapezoidal cross section when the dip of the coal seam is […], a special and an inclined arch cross section when […]. Eventually, a support system of bolts and cables combined with steel mesh and steel belts was provided. The support system used optimized material and improved parameters, can enhanced the self-bearing ability of the surrounding coal and rock masses.
Technologia utrzymywania chodników w obszarze zrobów w nachylonych pokładach węgla jest nadal rozwijana i udoskonalana. Jej zastosowanie prowadzi do zawału głównego stropu, który jednak w nieznacznym tylko stopniu wpływa na stabilność chodników z uwagi na odległość obszaru podsadzania, podczas gdy oddziaływania dynamiczne na chodniki przewozowe będą niewielkie. Powstały rozkład naprężeń wskazuje, że zastosowanie tej technologii w stromych pokładach przyniesie znaczne korzyści. Ponadto, w celu wzmocnienia warstw skał płonnych i miękkich warstw spągowych, a także dla lepszego zabezpieczenia przed skutkami ruchów skał płonnych w trakcie podsadzania, opracowano urządzenia blokujące ruch skał wraz ze wzmocnieniem cementowym. Obliczenia teoretyczne wskazują że zastosowana blokada ruchów skał charakteryzuje się wysokim wskaźnikiem bezpieczeństwa. Ponadto, opracowano także zestaw wsporników hydraulicznych dla dodatkowego wzmocnienia strefy podsadzania. Z uwagi na to, że zachowanie chodnika przewozowego jest działaniem stałym i systematycznym, dobór wymiarów i kształtu przekroju chodnika oraz metody jego stabilizacji jest sprawą kluczową już na etapie drążenia chodnika. W kroku pierwszym określono więc szerokość chodnika w jego dolnej części oraz wysokość stropu zgodnie z odpowiednimi wymogami. Następnie w oparciu o wymiary przekrojów 75 statystycznych chodników oraz uwzględniając dostępne techniki stabilizacji stropu wybrano przekrój trapezoidalny gdy nachylenie pokładu węgla mieści się w przedziale […], zaś dla kątów nachylenia w przedziale […] wybrano nachylony profil łukowy. W etapie końcowym zastosowano układ stabilizujący oparty na kotwach i kablach połączonych siatka stalową i stalowymi taśmami. W systemie stabilizującym wykorzystano zoptymalizowane materiały zapewniając lepsze parametry pracy, co korzystanie wpłynie na nośność warstw górotworu w otoczeniu pokładu węgla.
Źródło:
Archives of Mining Sciences; 2018, 63, 3; 599-616
0860-7001
Pojawia się w:
Archives of Mining Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł

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