Autor: Tang, Song - Prolib Integro

Skocz do pozycji: 1.

Tytuł:: Stability of transverse vibration of drillstring conveying drilling fluid
Autorzy:: Tang, Song
Liang, Zheng
Zhao, Guang-Hui
Tematy:: drillstring, fluid-pipe coupling
fluctuating WOB
stability
Galerkin method; Pokaż więcej
Wydawca:: Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Powiązania:: https://bibliotekanauki.pl/articles/1839591.pdf Link otwiera się w nowym oknie
Opis:: In this paper, an analytical model is proposed to predict lateral vibration of a drillstring in a vertical well. The effect of parameters, such as stiffness of spring, average weight on bit (WOB), amplitude of fluctuating WOB and so on, on the dynamic stability of the drillstring is discussed. It is found that the interaction between the drillstring and drilling mud has a great influence on drillstring buckling and dynamics. For constant drilling pressure, the mud flow rate stabilizes the drillstring under certain conditions, but the fluctuating WOB drives the drillstring parametric resonance.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: Characteristics of sandstone unloading creep and modelling for safe tunnel construction under high perimeter pressure and high pore water pressure condition
Autorzy:: Song, Li
Tang, Fujun
Kong, Dehui
Tematy:: model Burgersa
ciśnienie ograniczające
kryterium wytrzymałości Mohra-Coulomba
ciśnienie wody w porach
powierzchnia pęknięcia
pełzanie rozładowujące
piaskowiec
tunel
Burgers model
confining pressure
Mohr-Coulomb strength criterion
pore water pressure
rupture surface
unloading creep
sandstone
tunnel; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czasopisma i Monografie PAN
Powiązania:: https://bibliotekanauki.pl/articles/59111099.pdf Link otwiera się w nowym oknie
Opis:: Research on the properties of sandstone in the tunnel environment has been conducted due to the building industry’s rapid development, which is gradually involving underground water. Sandstone used in tunnel construction is susceptible to high perimeter and water pressures as a result of the abundance of sand and gravel close to groundwater, which might result in mishaps resembling collapses. The modified Burgers Model for the Malm dataset is the foundation of this study, which aims to reduce the internal crack extension caused by sandstone’s unloading creep. First, the study increased the material’s Poisson’s ratio in accordance with the Mohr-Coulomb strength criterion and builds a triaxial loading model on its foundation. Next, it analyzed the extension of the fracture surface of sandstone while taking high peripheral pressure and high hydraulic pressure into account. Finally, it discretized the unloading creep of sandstone using the improved Burgers model. On the basis of the model put forward in the study, experimental validation was then done on the Malm dataset. The sandstone would reach the final rupture area without any protection measures in just 10 days, but the model suggested in the study can delay this time to 200 days, while the effects of the other three models would delay this time by 75, 60, and 41 days, respectively. The model’s breadth was indicated by the linear fit value of 0.9827 for 36 experiments. The experimental findings demonstrated that the model suggested in the study can successfully lower the rate of sandstone unloading creep and increase worker safety.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Impact of the Mixture of Hexa(N-hydroxymethyl)amidocyclotriphosphazene and Partially Methylated Melamine Formaldehyde Resin on the Flame Retardancy of Paper
Wpływ mieszaniny hexa(N-hydroksymetylo)amidocyklotrifosfazenu i częściowo zmetylowanej żywicy melaminowoformaldehydowej na zmniejszenie palności papieru
Autorzy:: Tang, L.
Zhao, J.
Sui, X.
Song, H.
He, W.
Tematy:: hexa(N-hydroxymethyl)amidocyclotriphosphazene
partially methylated
melamine formaldehyde resin
flame retardancy
paper
hexa(N-hydroksymetyl)amidocyklotrifosfazen
ognioodporność
palność papieru; Pokaż więcej
Wydawca:: Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Powiązania:: https://bibliotekanauki.pl/articles/232388.pdf Link otwiera się w nowym oknie
Opis:: The flame retardancy of the mixture of hexa(N-hydroxymethyl)amidocyclotriphosphazene and partially methylated melamine formaldehyde resin (HHMATP/PMMM) in paper was proposed by limiting oxygen index measurement (LOI), the vertical burning test and cone calorimetry test (CCT). In our research, the LOI of washed FR-paper could still be up to 33.5%; the after flame time , and burning time were reduced to 4.8 s & 0 s, and the char length was only 12.0 mm. While the results of CCT imply that compared with non-flame retarded paper, the heat release rate (HRR) of FR-paper with HHMAPT/PMMM increases gently; the mass loss becomes significantly slow, and the prolonged maximum heat release rate (PHRR), average heat release rate (MHRR), average effective heat of combustion (MEHC) and total heat release (THR) drop greatly. According to the experimental results, HHMATP/PMMM has not only excellent flame retardancy in paper but also good water resistance, with HHMATP/PMMM playing a flame retardant role mainly by means of the condensed phase mechanism.
Badano zmniejszenie palności papieru stosując mieszaninę hexa(N-hydroxymethyl)amidocyclotriphosphazene i częściowo zmetylowanej żywicy melamine formaldehyde (HHMATP/PMMM) poprzez indeks tlenowy (LOI), test pionowego palenia i test kalorymetru stożkowego (CCT). Eksperymenty wykazały, że HHMATP/PMMM ma nie tylko dobry wpływ na ograniczenie palności papieru, ale również na jego odporność na działanie wody.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: Average capacity analysis of FSO system with Airy beam as carrier over exponentiated Weibull channels
Autorzy:: Li, Yi
Chu, Xingchun
Han, Zhongxiang
Tang, Hanling
Song, Xinkang
Tematy:: Airy beam
free-space optical communication
channel capacity
exponentiated Weibull model; Pokaż więcej
Wydawca:: Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Powiązania:: https://bibliotekanauki.pl/articles/2202763.pdf Link otwiera się w nowym oknie
Opis:: Based on scintillation index of Airy beam and exponentiated Weibull channel model, analytical expressions of average channel capacity for free-space optical (FSO) communication links with Airy beam as signal carrier under weak atmospheric turbulence and on-off keying modulation scheme are derived. The average capacity at various propagation distances, transverse scale factors and exponential decay factors has been evaluated. And we compared the average capacity of FSO links with Airy beam and Gaussian beam as signal carrier. The results show that the average capacity of FSO links with Airy beam as carrier increases with the increase of mean signal-to-noise ratio and decreases uniformly with the increase of propagation distance. When the transverse scale factor of Airy beam is about 2 cm, a higher average capacity can be obtained. And the smaller the exponential decay factor of Airy beam, the larger the average capacity. Under the same source power or source width, the average capacity of FSO links with Airy beam as carrier is significantly higher than that of FSO links with Gaussian beam as carrier. The results of this research have some reference significance for the application of Airy beam in FSO communication system.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 5.

Tytuł:: Impact of Hexaamidocyclotriphosphazene on the Flame Retardancy of Paper
Wpływ hexaamidocyklotrifosfazenu na zmniejszenie palności papieru
Autorzy:: Tang, L.
Bi, W.
Ke, Y.
Song, H.
He, W.
Liu, Y.
Tematy:: hexaamidocyclotriphosphazene
flame retardancy
paper
flame retarded paper
hexaamidocyklotrifosfazen
ognioodporność
palność papieru; Pokaż więcej
Wydawca:: Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Powiązania:: https://bibliotekanauki.pl/articles/232082.pdf Link otwiera się w nowym oknie
Opis:: In this paper, the flame retardancy of hexaamidocyclotriphosphazene (HACTP) in paper was studied by limiting oxygen index measurement, the vertical burning test and cone calorimetry test. Meanwhile the mechanism was discussed by the analysis of residues obtained in the cone calorimeter test. The experimental results revealed that HACTP had excellent flame retardancy in paper.
Badano zmniejszenie palności papieru stosując hexaamidocyklotrifosfazen (HACTP) poprzez indeks tlenowy, test pionowego palenia, i test kalorymetru stożkowego. Badano również mechanizm ograniczenia palności poprzez analizę resztek uzyskanych z testu kalorymetru stożkowego. Eksperymenty wykazały, że HACTP ma wybitny wpływ na zmniejszenie palności papieru.
Dostawca treści:: Biblioteka Nauki