Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

Wyszukujesz frazę "Li, Xiao" wg kryterium: Autor


Tytuł:
Design and Experiments of A New Internal Cone Type Traveling Wave Ultrasonic Motor
Autorzy:
Chen, Ye
Yang, Junlin
Li, Liang
Xiao, Shihao
Powiązania:
https://bibliotekanauki.pl/articles/31339802.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
ultrasonic motors
traveling wave
internal cone type
bending vibration
Opis:
In order to simplify the motor structure, to reduce the difficulty of rotor pre-pressure application and to obtain better output performance, a new internal cone type rotating traveling wave ultrasonic motor is proposed. The parametric model of the internal cone type ultrasonic motor was established by the ANSYS finite element software. The ultrasonic motor consists of an internal cone type vibrator and a tapered rotor. The dynamic analysis of the motor vibrator is carried out, and two in-plane third-order bending modes with the same frequency and orthogonality are selected as the working modes. The other advantages of this motor are that pre-pressure can be imposed by the weight of the rotor. The prototype was trial-manufactured and experimentally tested for its vibration characteristics and output performance. When the excitation frequency is 22260.0 Hz, the pre-pressure is 0.1 N and the peak-to-peak excitation voltage is 300 V, the maximum output torque of the prototype is 1.06 N · mm, and the maximum no-load speed can reach 441.2 rpm. The optimal pre-pressure force under different loads is studied, and the influence of the pre-pressure force on the mechanical properties of the ultrasonic motor is analyzed. It is instructive in the practical application of this ultrasonic motor.
Źródło:
Archives of Acoustics; 2023, 48, 3; 373-380
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ordovician spatial patterns of climate change inferred from isotope thermometers
Autorzy:
Ma, Xiao-Li
Fan, Yunxuan
Powiązania:
https://bibliotekanauki.pl/articles/24202132.pdf
Data publikacji:
2023
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
Ordovician
isotopes
Opis:
Ordovician was an extremely turbulent period for the Earth system, where the Great Ordovician Biodiversification Event (GOBE) occurred in the early-middle Ordovician. Many hypotheses were proposed, taking into account both biotic and abiotic factors. One such hypothesis posits that global cooling led to a transition from greenhouse to icehouse climate systems, which further triggered feedback mechanisms such as increased oceanic circulation, bio-productivity, and oxygenation during the middle Ordovician. Direct evidence, however, is still scarce. Here, we have compiled a comprehensive dataset of δ18O (10,636) from carbonate rocks and fossil shells as well as clumped isotope temperature data (Δ47; 88) spanning the entire Ordovician. Our study investigates climate change from both temporal and spatial perspectives. We assessed the effects of the late diagenesis alteration, lithological differences, different depositional environments and water depths on the carbonate δ18O, and corrected the latitudinal effect of the δ18O in seawater. The latitudinal temperature gradient (LTG) was introduced to account for the spatial patterns of climate change, which here refers to the difference in sea-surface temperature between low (<20°) and low-to-middle (20–40°) latitudes. We observed a gradual increase in the LTG from Tremadocian to Dapingian, indicating an amplified thermal contrast between low and low-middle latitudes. It suggested a remarkable climate cooling and shift towards an icehouse climate state, coinciding with the GOBE. From Darriwilian to Sandbian, the LTG weakens significantly and the temperature difference decreases, which is consistent with the plateau of global temperatures and the slow change in species diversity. After Sandbian, a progressive steepening of LTG was observed, which provides the first evidence for low paradoxical atmospheric CO2 at the Late Ordovician. Our study supports the global cooling hypothesis and sheds light on the links between climate change and biological evolution across the Ordovician.
Źródło:
Geotourism / Geoturystyka; 2023, 1-2 (72-73); 45--45
1731-0830
Pojawia się w:
Geotourism / Geoturystyka
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Flow field characteristic analysis of cushion system of partial air cushion support catamaran in regular waves
Autorzy:
Yang, Jinglei
Sun, Han-bing
Li, Xiao-wen
Liu, Xin
Powiązania:
https://bibliotekanauki.pl/articles/32910719.pdf
Data publikacji:
2022
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
regular waves
partial air cushion support catamaran (PACSCAT)
cushion system
fluid structure interaction (FSI)
flow field characteristics
Opis:
In order to study the flow field characteristics of cushion system of partial air cushion support catamaran (PACSCAT) in waves, an analysis was carried out involving flexible treatment on the bow and stern air seals to simulate air seal shape under test conditions by means of computational fluid dynamics method and fluid structure interaction (FSI) method. On this basis, the pressure conditions of the air cushion chamber and the pressurized chamber at different wavelengths and different speeds are studied and compared with experimental results. The experimental results show that: for the air cushion pressure, the nonlinear characteristics of the numerical calculation results are more subtle than the experimental values, after linear transformation, the amplitudes of the experimental values are obviously greater than the calculated values after linear transformation, but the average values are not much different; At low speed of 2.0m/s, the spatial pressure distribution of the pressurized chamber and the air cushion chamber are uniformly distributed, at high speed of 3.6m/s, except for a certain pressure jump occurred in the air cushion chamber near the stern air seal, the pressure in other spaces is also evenly distributed, it proves that the pressurized chamber type of air intake can effectively meet the air cushion pressure balance.
Źródło:
Polish Maritime Research; 2022, 3; 21-32
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Model predictive control of NPC three-level grid-tied converter based on reconstructed current
Autorzy:
Li, Yanyan
Xiao, Han
Jin, Nan
Yan, Guanglu
Powiązania:
https://bibliotekanauki.pl/articles/2086686.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
current reconstruction
current sensor fault
fault-tolerant
model predictive control
neutral point clamped three-level converter
Opis:
The neutral point clamped (NPC) three-level grid-tied converter is the key equipment connecting renewable energy and power grids. The current sensor fault caused by harsh environment may lead to the split of renewable energy. The existing sensor fault-tolerant methods will reduce the modulation ratio index of the converter system. To ensure continuous operation of the converter system and improve the modulation index, a model predictive control method based on reconstructed current is proposed in this paper. According to the relationship between fault phase current and a voltage vector, the original voltage vector is combined and classified. To maintain the stable operation of the converter and improve the utilization rate of DC voltage, two kinds of fault phase current are reconstructed with DC current, normal phase current and predicted current, respectively. Based on reconstructed three-phase current, a current predictive control model is designed, and a model predictive control method is proposed. The proposed method selects the optimal voltage vector with the cost function and reduces time delay with the current reconstruction sector. The simulation and experimental results show that the proposed strategy can keep the NPC converter running stably with one AC sensor, and the modulation index is increased from 57.7% to 100%.
Źródło:
Archives of Electrical Engineering; 2022, 71, 2; 363--377
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
RFID tag group recognition based on motion blur estimation and YOLOv2 improved by Gaussian algorithm
Autorzy:
Li, Lin
Yu, Xiao-Lei
Liu, Zhen-Lu
Zhao, Zhi-Min
Zhang, Ke
Zhou, Shan-Hao
Powiązania:
https://bibliotekanauki.pl/articles/2051852.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
RFID
YOLOv2
neural network
GRNN
Opis:
Effective recognition of tags in the dynamic measurement system would significantly improve the reading performance of the tag group, but the blurred outline and appearance of tag images captured in motion seriously limit the effectiveness of the existing tag group recognition. Thus, this paper proposes passive tag group recognition in the dynamic environment based on motion blur estimation and improved YOLOv2. Firstly, blur angles are estimated with a Gabor filter, and blur lengths are estimated through nonlinear modelling of a Generalized Regression Neural Network (GRNN). Secondly, tag recognition based on YOLOv2 improved by a Gaussian algorithm is proposed. The features of the tag group are analyzed by the Gaussian algorithm, the region of interest of the dynamic tag is effectively framed, and the tag foreground is extracted; Secondly, the data set of tag groups are trained by the end-to-end YOLOv2 algorithm for secondary screening and recognition, and finally the specific locations of tags are framed to meet the effective identification of tag groups in different scenes. A considerable number of experiments illustrate that the fusion algorithm can significantly improve recognition accuracy. Combined with the reading distance, the research presented in this paper can more accurately optimize the three-dimensional structure of the tag group, improve the reading performance of the tag group, and avoid the interference and collision of tags in the communication channel. Compared with the previous template matching algorithm, the tag group recognition ability put forward in this paper is improved by at least 13.9%, and its reading performance is improved by at least 6.2% as shown in many experiments.
Źródło:
Metrology and Measurement Systems; 2022, 29, 1; 53-74
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of Motivational Conditions Behind Sustainable Consumption in Chinas Uniform Market
Analiza warunków motywacyjnych stojących za zrównoważoną konsumpcją na jednolitym rynku w Chinach
Autorzy:
Zhang, Ying
Li, Li
Xing, Xue
Liu, Xiao-Gang
Powiązania:
https://bibliotekanauki.pl/articles/1857707.pdf
Data publikacji:
2021
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:
China's uniform market
sustainable consumption
eco-friendly fabric
environmental awareness
uniform
zrównoważona konsumpcja
tkanina ekologiczna
świadomość ekologiczna
Opis:
A uniform is distinctive clothing worn by members of the same firm or organisation. In China, the market for professional garments is extremely large. However, as mandatory professional clothing, uniforms are frequently used, torn, and replaced, leading to textile waste. Further, the use of non-recyclable or non-biodegradable fabrics is bound to create greater environmental pressure. This study focuses on the textile material in the uniform market to analyse the motivational conditions behind sustainable fabric consumption. A total of 294 usable online surveys were obtained in 2019. Multi-item scales were adopted to measure five variables: corporate public image, corporate ethics, employee social status, environment awareness, and sustainable premium. Structural equation modelling was applied to test the hypothesises. Results reveal that the improvement of an employee's social status can effectively facilitate the probability of utilising eco-friendly fabrics. This study can thus help increase the usage of eco-friendly fabric in China’s uniform market.
Uniform to charakterystyczna odzież noszona przez członków tej samej firmy lub organizacji. W Chinach rynek odzieży profesjonalnej jest niezwykle duży. Jednak, jako obowiązkowa odzież zawodowa, uniformy są często używane i wymieniane, co prowadzi do marnotrawstwa tekstyliów. Ponadto stosowanie nienadających się do recyklingu lub nieulegających biodegradacji tkanin może powodować większą presję na środowisko. W badaniu skoncentrowano się na materiale tekstylnym na rynku jednolitym, przeanalizowano motywacyjne warunki stojące za zrównoważoną konsumpcją tkanin. W 2019 roku uzyskano łącznie 294 użytecznych ankiet on-line. Do pomiaru pięciu zmiennych: wizerunku publicznego firmy, etyki korporacyjnej, statusu społecznego pracowników, świadomości środowiskowej i zrównoważonej składki zostały przyjęte skale wielopozycyjne. Do testowania hipotez zastosowano modelowanie równań strukturalnych. Wyniki pokazały, że poprawa statusu społecznego pracownika może skutecznie zwiększyć prawdopodobieństwo używania tkanin przyjaznych dla środowiska. Badanie to może zatem pomóc w zwiększeniu wykorzystania tkanin przyjaznych dla środowiska na jednolitym rynku Chin.
Źródło:
Fibres & Textiles in Eastern Europe; 2021, 4 (148); 8-14
1230-3666
2300-7354
Pojawia się w:
Fibres & Textiles in Eastern Europe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of chromatographic plate theory on the weathered crust elution-deposited rare earth ore with carboxylate
Autorzy:
Zhang, Zhenyue
Wang, Guangshuai
Li, Chunhua
Chi, Ruan
Long, Fei
Chen, Zhuo
Chi, Xiao Wang
Liu, Defeng
Powiązania:
https://bibliotekanauki.pl/articles/1446022.pdf
Data publikacji:
2021
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
weathered crust elution-deposited rare earth ore
carboxylate ammonium
mass transfer
theory plate
rare earth
Opis:
To improve the leaching process of rare earth and reduce the impurities in the leachate, the carboxylate ammonium, such as ammonium acetate, ammonium citrate and ammonium tartrate, were selected as lixiviant to compare the effects of concentration, flow rate, pH and temperature on leaching mass process of rare earth and aluminum. Meanwhile, the leaching behaviors of rare earth and aluminum leached by three kinds of carboxylate ammonium were analyzed by chromatographic plate theory. The relationship between the flow rate and height equivalent (HETP) could fit well with the Van Deemter equation and there was an optimal flow rate (uopt) for the leaching of the rare earth and aluminum. Besides, the conditions of carboxylate ammonium lixiviant were optimized. The optimum concentrations of ammonium acetate, ammonium tartrate and ammonium citrate were 15 g/L, 25 g/L and 5 g/L respectively, the leaching flow rate was 0.50 mL/min, the pH value was approximatively 7.00 and the leaching temperature was 293 K to 303 K. At these conditions, the mass transfer efficiencies of three ammonium carboxylates for rare earth and aluminum was in the order of ammonium acetate > ammonium tartrate > ammonium citrate. Moreover, the ammonium acetate could commendably inhibit aluminum ions entering the lixivium.
Źródło:
Physicochemical Problems of Mineral Processing; 2021, 57, 4; 48-62
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of Ageratina adenophora on hepatic and pulmonic pathological lesions in horses
Autorzy:
Gu, X.L.
Dai, F.Y.
Xiao, X.
Li, G.Z.
Zhang, L.M.
Qu, W.J.
Powiązania:
https://bibliotekanauki.pl/articles/2087129.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Ageratina adenophora
liver
lung
horse
toxicity
Źródło:
Polish Journal of Veterinary Sciences; 2021, 24, 4; 611-613
1505-1773
Pojawia się w:
Polish Journal of Veterinary Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research on ship trajectory extraction based on multiattribute DBSCAN optimisation algorithm
Autorzy:
Xu, Xiaofeng
Cui, Deqaing
Li, Yun
Xiao, Yingjie
Powiązania:
https://bibliotekanauki.pl/articles/1551877.pdf
Data publikacji:
2021
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
clustering algorithm
abnormal route
DBSCAN
feature trajectory extraction
fitting analysis
Opis:
With the vigorous development of maritime traffic, the importance of maritime navigation safety is increasing day by day. Ship trajectory extraction and analysis play an important role in ensuring navigation safety. At present, the DBSCAN (density-based spatial clustering of applications with noise) algorithm is the most common method in the research of ship trajectory extraction, but it has shortcomings such as missing ship trajectories in the process of trajectory division. The improved multi-attribute DBSCAN algorithm avoids trajectory division and greatly reduces the probability of missing sub-trajectories. By introducing the position, speed and heading of the ship track point, dividing the complex water area and vectorising the ship track, the function of guaranteeing the track integrity can be achieved and the ship clustering effect can be better realised. The result shows that the cluster fitting effect reaches up to 99.83%, which proves that the multi-attribute DBSCAN algorithm and cluster analysis algorithm have higher reliability and provide better theoretical guidance for the analysis of ship abnormal behaviour.
Źródło:
Polish Maritime Research; 2021, 1; 136-148
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A dynamic model for the heat transfer behavior of a cooling system
Autorzy:
Liu, Wen
Zhang, Chi
Hu, Xiao-Xiong
Cao, Jian-Bo
Liu, Li-Jiao
Ye, Xin-Y
Lin, Li
Qi, Xun-Ji
Powiązania:
https://bibliotekanauki.pl/articles/2050060.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
adsorption system
refrigerating system
desorption
simulation
Opis:
For purposes of studying the heat transfer behavior of various fluids in a refrigeration system, a dynamic model is established, obtained on the basis of analysis concerning the effects of adsorption velocity, adsorbent bed temperature, condensing temperature, and heat transfer fluids, as well as changes of external conditions. It is demonstrated that adsorption velocity increases sharply in the initial phase of adsorption process and gradually declines after reaching a peak value, whereas condensing temperature increases sharply in the initial phase of desorption process and decreases after reaching a peak value with the desorption quantity decreasing. Furthermore, the increase of heat source temperature and the decrease of cooling water temperature can advance the adsorption process. The present study therefore suggests some ways of improving the performance of such a refrigeration system by increasing heat source temperature, decreasing ambient air temperature, increasing return air temperature and decreasing cooling water temperature.
Źródło:
Control and Cybernetics; 2020, 49, 3; 315--332
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A new low SNR underwater acoustic signal classification method based on intrinsic modal features maintaining dimensionality reduction
Autorzy:
Ju, Yang
Wei, Zhengxian
Li, Huangfu
Feng, Xiao
Powiązania:
https://bibliotekanauki.pl/articles/259300.pdf
Data publikacji:
2020
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
acoustic
low SNR
signal classification
feature maintain
dimension reduction
Opis:
The classification of low signal-to-noise ratio (SNR) underwater acoustic signals in complex acoustic environments and increasingly small target radiation noise is a hot research topic. . This paper proposes a new method for signal processing—low SNR underwater acoustic signal classification method (LSUASC)—based on intrinsic modal features maintaining dimensionality reduction. Using the LSUASC method, the underwater acoustic signal was first transformed with the Hilbert-Huang Transform (HHT) and the intrinsic mode was extracted. the intrinsic mode was then transformed into a corresponding Mel-frequency cepstrum coefficient (MFCC) to form a multidimensional feature vector of the low SNR acoustic signal. Next, a semi-supervised fuzzy rough Laplacian Eigenmap (SSFRLE) method was proposed to perform manifold dimension reduction (local sparse and discrete features of underwater acoustic signals can be maintained in the dimension reduction process) and principal component analysis (PCA) was adopted in the proces of dimension reduction to define the reduced dimension adaptively. Finally, Fuzzy C-Means (FCMs), which are able to classify data with weak features was adopted to cluster the signal features after dimensionality reduction. The experimental results presented here show that the LSUASC method is able to classify low SNR underwater acoustic signals with high accuracy.
Źródło:
Polish Maritime Research; 2020, 2; 187-198
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental and numerical study on the classification of a cyclonic field in a flotation column
Autorzy:
Li, Xiaoheng
Li, Xiao
Yan, Xiaokang
Wang, Lijun
Zhang, Haijun
Powiązania:
https://bibliotekanauki.pl/articles/109487.pdf
Data publikacji:
2020
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
computational fluid dynamics
cyclonic flow field
cyclonic-static micro-bubble flotation column
particle size distribution
Opis:
The cyclonic-static micro-bubble flotation column (FCSMC) performs well in fine mineral flotation. Compared to traditional flotation columns, its design innovatively introduces a cyclonic structure. The separation of middling and tailing occurs in the cyclonic flow field induced by a cyclonic reversal cone. In this study, the particle size distribution analysis and computational fluid dynamics (CFD) simulations were conducted to reveal the particle distribution law and the classification mechanism in cyclonic flow fields under different circulation pressures. The results showed that particle size showed the same distribution tendency as tangential velocity in the radial direction: both increase from the center and decrease around the wall. As circulation flux increased, the tangential velocity increased, and the particle size differences in the radial direction also increased. The position of the largest particles will move to outside as the largest value of tangential velocity migrates the outward in the radial direction. According to the particle size distribution of the feed, it can be adjusted to the flow field to change the particle distribution, thereby improving the efficiency of separation. This study has an important guiding significance for column design and adjustment of the operating parameters of the flotation process.
Źródło:
Physicochemical Problems of Mineral Processing; 2020, 56, 3; 421-431
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Flotation separation of rutile from almandine using octadecyl amine polyoxyethylene ether as collector
Autorzy:
Li, Hongqiang
Zheng, Huifang
Chen, Qian
Kasomo, Richard M.
Leng, Jiahao
Weng, Xiaoqing
Song, Shaoxian
Xiao, Linbo
Tian, Chengtao
Powiązania:
https://bibliotekanauki.pl/articles/1449410.pdf
Data publikacji:
2020
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
rutile
almandine
flotation separation
adsorption mechanism
Opis:
In this study, the flotation separation of rutile from almandine using cationic surfactant Octadecyl amine polyoxyethylene ether (AC1815) as a new collector was investigated. The adsorption mechanism of AC1815 on rutile was illustrated through zeta potential measurement, infrared spectrum and XPS analyses. The flotation experiments demonstrated that AC1815 exhibited an excellent collecting ability and selectivity for rutile. The results of zeta potential measurements and XPS analysis indicated that more AC1815 was adsorbed on rutile surface instead of almandine. The adsorption mechanism of AC1815on rutile was mainly attributed to the electrostatic interaction between the positively charged molecules of AC1815 and the negatively charged rutile surface, and the hydrogen bonding between the protonated $≡NH^+$, $≡N$ group of AC1815 and $Ti-OH$ on rutile surface.
Źródło:
Physicochemical Problems of Mineral Processing; 2020, 56, 4; 653-664
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
MANDARIN DISCRIMINATION IN HONG KONG: FOUR MAINLAND CHINESE SOJOURN TEACHERS’ EXPERIENCE OF SYMBOLIC VIOLENCE
Autorzy:
Li, Yulong
Xiao, Daibo
Powiązania:
https://bibliotekanauki.pl/articles/628671.pdf
Data publikacji:
2020
Wydawca:
Fundacja Pro Scientia Publica
Tematy:
Mandarin discrimination
symbolic violence
anti-colonialism
Hong Kong
Opis:
Thesis. After the handover of Hong Kong’s sovereignty to China in 1997, the Hong Kong Special Administrative Region government stipulated a trilingual (English, Cantonese, and Mandarin) and biliterate (English and Chinese) policy, in order to include Mandarin as an additional co-official language together with the original English and Cantonese. Until the handover, the use of Mandarin was restricted in British colonial Hong Kong. Since the handover, however, Mandarin and its users have experienced some resistance by local Hong Kong people. Method. In an attempt to better understand this resistance and its implications, this study adopts Pierre Bourdieu’s field, habitus, and capital theory, to analyse the anti-Mandarin discourse that has prevailed in the ensuing two decades. Via narrative inquiry, this study explains the habitus of four Mandarin speaking teachers, while especially noting their clashes with the anti-Mandarin discourse, and the symbolic violence they suffered in the field.     Conclusion. The study concludes with a reflection on the clash between the teachers’ struggles with the discourse from a postcolonial perspective, and it also considers the legal issues involved in protecting mainland Chinese as a minority in Hong Kong.
Źródło:
Journal of Education Culture and Society; 2020, 11, 2; 499-520
2081-1640
Pojawia się w:
Journal of Education Culture and Society
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Microcellular Oblate Propellant with Skin-core Structure Deterred by Poly(neopentanediol adipate)
Autorzy:
Ding, Yajun
Ying, Sanjiu
Xiao, Zhongliang
Wu, Wenlong
Li, Chunzhi
He, Yun
Powiązania:
https://bibliotekanauki.pl/articles/358225.pdf
Data publikacji:
2020
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
SC-CO2
microcellular oblate propellant
skin-core structure
poly(neopentanediol adipate) deterring
combustion performance
Opis:
In order to solve the issues of high muzzle flash, smoke, residue, migration rate and carcinogenicity of double-base oblate propellants deterred by dibutyl phthalate (DBP), skin-core structure microporous oblate propellants to replace DBP deterring technology were fabricated in the present work by supercritical carbon dioxide (SC-CO2) foaming technology. Poly(neopentanediol adipate) (NA) was employed as the deterrent to modify the combustion properties because of ist lower migration rate in storage. Scanning electron microscopy (SEM) was used to observe the morphology of the microporous oblate propellants generated by different processing conditions, and the combustion properties were investigated by closed bomb tests. The SEM images indicated that the skin region displayed smaller cell diameters and lower cell density compared with cells in the core region. The closed bomb tests demonstrated that it was feasible to adjust the progressive combustion performance by controlling the skin-core structure and the NA deterred layer. The burning time values of the original, the microcellular, and the NA deterred samples were 3.45, 2.14, and 4.20 ms, respectively. Microcellular oblate propellants, with a skin-core structure foamed by SC-CO2 and deterred by NA, provides a novel and promising method to realize progressive combustion performance.
Źródło:
Central European Journal of Energetic Materials; 2020, 17, 1; 49-65
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł

Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies