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Wyszukujesz frazę "Jiang, Yan" wg kryterium: Autor


Wyświetlanie 1-9 z 9
Tytuł:
A new prediction model of surface subsidence with cauchy distribution in the coal mine of thick topsoil condition
Autorzy:
Jiang, Yue
Misa, Rafał
Tajduś, Krzysztof
Sroka, Anton
Jiang, Yan
Powiązania:
https://bibliotekanauki.pl/articles/219750.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
wydobycie węgla
osiadanie powierzchni
rozkład Cauchy'ego
model obliczeniowy
coal mining
thick topsoil
surface subsidence
Probability Integral Method
Cauchy distribution
calculation model
Opis:
Coal is the main energy source in China, but its underground mining causes surface subsidence, chich seriously damages the ecological and living environments. How to calculate subsidence accurately is a core issue in evaluating mining damage. At present, the most commonly used method of calculation is the Probability Integral Method (PIM), based on a normal distribution. However, this method has limitations in thick topsoil (thickness > 100 m), in that the extent of the calculated boundary of the subsidence basin is smaller than its real extent, and this has an undoubted impact on the accurate assessment of the extent of mining damage. Therefore, this paper introduces a calculation model for surface subsidence based on a Cauchy distribution for thick topsoil conditions. This not only improves the accuracy of calculation at the subsidence basin boundary, but also provides a universal method for the calculation of surface subsidence.
Źródło:
Archives of Mining Sciences; 2020, 65, 1; 147-158
0860-7001
Pojawia się w:
Archives of Mining Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
In-fiber Mach–Zehnder interferometer based on polarization-maintaining fiber for displacement and temperature sensing
Autorzy:
Cheng, Jun-Ni
Jiang, Xiao-Yan
Powiązania:
https://bibliotekanauki.pl/articles/2202764.pdf
Data publikacji:
2023
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
displacement sensing
polarization-maintaining fiber
graded-index multimode fiber
Mach-Zehnder interferometer
Opis:
A displacement sensor based on polarization-maintaining fiber has been proposed and proved in experiment. The polarization-maintaining fiber (PMF) is sandwiched with two graded-index multimode fibers (GI MMF), which form the Mach–Zehnder interferometer (MZI) sensor. Graded-index multimode fiber serve as an optical coupler for modes conversion. The results show that with the increase of displacement, the spectrum moves to the long wavelength direction, but when temperature increases, the spectrum has a red shift, which means that the displacement and temperature can be measured separately according to the wavelength drift direction. The sensor consists of 4 mm GI MMF and 14 mm PMF, which can exhibit the displacement sensitivity of –9.275 pm/μm in the range of 0–600 μm. In addition, temperature will also affect the sensitivity of displacement measurement, so the sensitivity of the sensor to temperature is also measured. The results show that the selected monitoring dip provides a better temperature sensitivity of 33.605 pm/°C in the range of 35–75°C. The sensor is easy to fabricate and does not has any functional coating, which make it become a good candidate in the industrial field.
Źródło:
Optica Applicata; 2023, 53, 1; 21--33
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A novel fault diagnosis method for marine blower with vibration signals
Autorzy:
Yan, Guohua
Hu, Yihuai
Jiang, Jiawei
Powiązania:
https://bibliotekanauki.pl/articles/32899234.pdf
Data publikacji:
2022
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
fault diagnosis
marine blower
EEMD
correlation coefficient
AR spectrum
BPNN
Opis:
The vibration signals on marine blowers are non-linear and non-stationary. In addition, the equipment in marine engine room is numerous and affects each other, which makes it difficult to extract fault features of vibration signals in the time domain. This paper proposes a fault diagnosis method based on the combination of Ensemble Empirical Mode Decomposition (EEMD), an Autoregressive model (AR model) and the correlation coefficient method. Firstly, a series of Intrinsic Mode Function (IMF) components were obtained after the vibration signal was decomposed by EEMD. Secondly, effective IMF components were selected by the correlation coefficient method. AR models were established and the power spectrum was analysed. It was verified that blower failure can be accurately diagnosed. In addition, an intelligent diagnosis method was proposed based on the combination of EEMD energy and a Back Propagation Neural Network (BPNN), with a correlation coefficient method to get effective IMF components, and the energy components were calculated, normalised as a feature vector. Finally, the feature vector was sent to the BPNN for training and state recognition. The results indicated that the EEMD-BPNN intelligent fault diagnosis method is suitable for higly accurate fault diagnosis of marine blowers.
Źródło:
Polish Maritime Research; 2022, 2; 77-86
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Problems and Solutions to the Undergraduates’ Free Option Power of Learning : A Case Study of One “211 project” University in Central China
Autorzy:
González, Juan Carlos
Liang, Yan
Jiang, Hongchi
Powiązania:
https://bibliotekanauki.pl/articles/1969385.pdf
Data publikacji:
2018-06-30
Wydawca:
Wydawnictwo Adam Marszałek
Tematy:
China
undergraduates
higher education
qualitative research
Opis:
Students’ free option power of learning is an important part of students’ power of learning. It emphasizes respect for students’ learning rights and freedom, so that students have a certain freedom of learning choice. In the theory and practice of Chinese higher education, undergraduates’ free option power of learning has long been weakened and restricted by various factors. This study provides an understanding of the current situation of undergraduates’ free option power of learning through 20 interviews with undergra duates from a university in Central China in a pilot project, whose purpose was to provide students with freedom in selecting higher education options. The interviews address three areas where students were given the option to select: (a) learning content, (b) learning processes, and (c) learning environments. Discussion follows on the problems experienced by Chinese undergraduates’ in the free option power of learning project. Lastly, as China hopes to expand this project beyond the pilot, we advance recommendations to promote effective implementation of the free option power of learning of Chinese undergraduates, such as: (a) establishing sound laws to ensure the effective implementation of the power of students; (b) empowering undergraduates to have more choice to choose and change their majors; (c) carrying out the flexible program duration to let students have free choice of getting credits; and (d) establishing a sound and perfect transfer mechanism to let students have more choice of universities.
Źródło:
The New Educational Review; 2018, 52; 218-232
1732-6729
Pojawia się w:
The New Educational Review
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Deep learning-based fault diagnosis for marine centrifugal fan
Autorzy:
Li, Congyue
Hu, Yihuai
Jiang, Jiawei
Yan, Guohua
Powiązania:
https://bibliotekanauki.pl/articles/32917700.pdf
Data publikacji:
2023
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
CEEMDAN
fault diagnosis
lightweight neural network
marine centrifugal fan
Opis:
Marine centrifugal fans usually work in harsh environments. Their vibration signals are non-linear. The traditional fault diagnosis methods of fans require much calculation and have low operating efficiency. Only shallow fault features can be extracted. As a result, the diagnosis accuracy is not high. It is difficult to realize the end-to-end fault diagnosis. Combining the Complete Ensemble Empirical Mode Decomposition with Adaptive Noise (CEEMDAN) and lightweight neural network, a fault classification method is proposed. First, the CEEMDAN can decompose the vibration signal into several intrinsic modal functions (IMF). Then, the original signals can be transformed into 2-D images through pseudocolour coding of the IMFs. Finally, they are fed into the lightweight neural network for fault diagnosis. By embedding a convolutional block attention module (CBAM), the ability of the network to extract critical feature information is improved. The results show that the proposed method can adaptively extract the fault characteristics of a marine centrifugal fan. While the model is lightweight, the overall diagnostic accuracy can reach 99.3%. As exploratory basic research, this method can provide a reference for intelligent fault diagnosis systems on ships.
Źródło:
Polish Maritime Research; 2023, 1; 112-120
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study on Mechanism and Suppression Method of Flow-Induced Noise in High-Speed Gear Pump
Autorzy:
Zhan, Peng
Qiang, Yan
Jiang, Zhiyuan
Yang, Runxue
Wei, Liejiang
Powiązania:
https://bibliotekanauki.pl/articles/31339742.pdf
Data publikacji:
2024
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
external gear pumps
flow-induced noise
the oil replenishment groove
flow pulsation rate
Opis:
The flow-induced noise mechanism of a 5000 rpm high-speed gear pump is explored. On the basis of the CFD technology and the Lighthill acoustic analogy theory, a numerical model of the flow-induced noise of a high-speed gear pump is constructed, and the effect of oil suction pressure (0.1–0.2 MPa) on the internal flow field and flow-induced noise characteristics of the high-speed gear pump is investigated. To evaluate the accuracy of the numerical simulation, a noise testing platform for high-speed gear pumps was developed. Adding an oil replenishment groove to the high-speed gear pump suppresses its flow-induced noise. The results indicate that the discrete noise at the fundamental frequency and its harmonic frequency is the primary component of the flow-induced noise of the pump and that the oil-trapped area is the principal source of vibration. The overall sound pressure level of flow-induced noise in the inlet and outlet areas decreases with distance from the oil-trapped area, and the sound pressure level in the outlet area is greater than that in the inlet area. The oil replenishment groove may considerably minimize cavitation noise, enhance the oil absorption capacity, and reduce the outer field’s overall sound pressure level by 4–5 dB.
Źródło:
Archives of Acoustics; 2024, 49, 1; 49-60
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Summer distribution patterns of Trichodesmium spp. in the Changjiang (Yangtze River) Estuary and adjacent East China Sea shelf
Autorzy:
Jiang, Z.
Chen, J.
Zhou, F.
Zhai, H.
Zhang, D.
Yan, X.
Powiązania:
https://bibliotekanauki.pl/articles/47907.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
Trichodesmium
Yangtze River
estuary
China Sea
trichome
biogeochemistry
environment parameter
sea surface temperature
salinity
Opis:
To examine the distribution of Trichodesmium relative to physicochemical factors during summer in the Changjiang (Yangtze River) Estuary and adjacent East China Sea shelf, three cruises were conducted separately in June 2009, July 2011, and August 2009. Trichodesmium species found were T. thiebautii, T. erythraeum, and T. hildebrandtii. The population was dominated by T. thiebautii, which accounted for >85% of the samples found. Most of them were free trichomes. Colonial forms were rarely observed (approximately 10% of our samples), occurring only in offshore waters. The depth integrated abundances of Trichodesmium were 308 × 103, 1709 × 103, and 3448 × 103 trichomes m−2 in June, July, and August, respectively. Trichodesmium was distributed abundantly in the southern or southeastern part of our study area, where nutrients were low and light penetration, temperature, and salinity were high, which were influenced by the Taiwan Warm Current (TWC) and Kuroshio. Trichodesmium was found in low abundance in inshore, eutrophic, low-salinity waters, which were mainly controlled by the Changjiang Diluted Water (CDW) and coastal current. These results suggest that spatiotemporal changes in the summer Trichodesmium distribution correlate highly with the variations in physicochemical properties that are primarily controlled by the TWC, Kuroshio, and CDW. The summer N2 fixation rate of Trichodesmium was estimated at 12.3 μmol N m−2 d−1 in our study area, contributing >50% of biological N2 fixation.
Źródło:
Oceanologia; 2017, 59, 3
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Seroepidemiological study of canine Leishmania infantum and Toxoplasma gondii infections in Shanghai, China, and analysis of risk factors
Autorzy:
Jiang, Wei
Wang, Yan
Liu, Yingchun
Li, Tao
Chen, Yongjun
Wang, Shaohui
Han, Xiangan
Wang, Quan
Powiązania:
https://bibliotekanauki.pl/articles/990968.pdf
Data publikacji:
2016
Wydawca:
Instytut Medycyny Wsi
Tematy:
seroprevalence
leishmania infantum
toxoplasma gondii
household dogs
risk factors
Opis:
The aim of this study was to determine the seroprevalence of Leishmania infantum and Toxoplasma gondii among household dogs in Shanghai (the most important industrial and commercial city in China), and to assess the possible risk factors associated with the infection. During 2014–2015, a total of 408 sera were collected from healthy household dogs and tested for L. infantum and T. gondii infection using commercial ELISA kits. The endemic characteristics according to gender, age group and breed were revealed by statistical descriptions and inference. The positive rates of L. infantum infection (24/408, 5.9%) were lower than those of T. gondii infection (37/408, 9.1%), and co-infection with both parasites was detected in seven dogs (7/408, 1.7%). Seropositivity for either parasite was more likely associated with age: the seroprevalence of T. gondii infection ranged from 1.3% (dogs≤1 year) – 18.7% (dogs>6 years), whereas that of L. infantum ranged from 1.3% (dogs≤1 year) – 9.9 % (dogs>6 years). Interestingly, the rates of exposure to both L. infantum and T. gondii were higher in males than in females. Relatively higher exposure rates for L. infantum and T. gondii were also observed in crossbred dogs compared with purebred dogs. However, neither gender nor breed is likely a determining factor for infection with these two parasites (P > 0.05). Identification of the risk factors that underlie these differences may help in the prevention of L. infantum and T. gondii infection in household dogs. To the best of our knowledge, this is the first report of L. infantum and T. gondii infection in household dogs in Shanghai, which shows that these two important parasites are still prevalent in this region. Therefore, it is necessary to take integrated strategies for prevention and control of infection in animals, which could help to reduce human infection in the region.
Źródło:
Annals of Agricultural and Environmental Medicine; 2016, 23, 3
1232-1966
Pojawia się w:
Annals of Agricultural and Environmental Medicine
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mitigation scratch on fused silica optics using CO2 laser
Autorzy:
Liu, C.-M.
Yan, Z.-H.
Yang, L.
Jiang, Y.
Zu, X.-T.
Wang, H.-J.
Liao, W.
Yuan, X.-D.
Zheng, W.-G.
Powiązania:
https://bibliotekanauki.pl/articles/174978.pdf
Data publikacji:
2016
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
mitigation
scratch
fused silica
CO2 laser
Opis:
The scratch on a fused silica surface was treated as a chain of connected damage sites and mitigated one after another using CO2 laser irradiation. The optical microscopy image shows that a scratch with the width of about 30 μm and length of several millimeters can be completely mitigated without the formation of debris and bubbles. The mitigated scratch can survive under raster scan laser irradiation with the fluency increased up to 11.0J/cm2 at 3ns and 351nm. On the contrary, the substrate without CO2 laser mitigation is seriously damaged under this irradiation. The light modulation induced by mitigation is much smaller when the scratch is mitigated before being damaged. The light modulation is about 2 when the distance to the mitigated sample is larger than 20cm. The birefringence induced by residual stress in the mitigated scratch is measured. The retardance of the mitigated scratch before being damaged is not visible. Therefore, residual stress in this mitigated scratch before being damaged should be not a critical potential risk in laser damage.
Źródło:
Optica Applicata; 2016, 46, 3; 387-397
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-9 z 9

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