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1
Content available Optimized design and analysis of offshore Beidou maritime foundation reinforcement system pseudolite ranging-codes
100%
Su D. , Zhou A. , Zhou Z. , Chen W.
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2017
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tom S 2
45--52
EN
Under the bad sea conditions and weak Beidou navigation signal environment, it is difficult to locate the ship on the sea, and the Beidou navigation system can’t work well. Beidou pseudolite system can improve the performance of Beidou navigation system as a navigation signal transmitter fixed on the ground, the signal of which can improve satellite positioning constellation structure, and improve the system availability reliability and precision. In order to ensure the interoperability and non-correlation of the Beidou pseudolite and the Beidou navigation system, the pseudolite ranging-codes should be selected in the same code space of the satellite ranging-codes and the residual pseudo random code generated by the 2 taps design scheme does not satisfy the performance requirements of the ranging-codes. To solve this issue, a combined design scheme with 3 taps is proposed, and 12 kinds of pseudolite ranging-codes are optimally selected according to the optimum design parameters of ranging-codes. The waveform and correlation of the selected pseudolite ranging-codes are analyzed by MATLAB, the acquisition simulation is carried out by using the new pseudolite ranging-codes. The experimental results show that the new 3-taps based ranging codes design scheme behaves a good balance, correlation and spectral characteristics.
2
Optimized design and analysis of offshore Beidou Maritime Foundation reinforcement system pseudolite ranging-codes
100%
Su D. , Zhou A. , Zhou Z. , Chen W.
Polish Maritime Research
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2017
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tom 24
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nr Special Issue S2
EN
Under the bad sea conditions and weak Beidou navigation signal environment, it is difficult to locate the ship on the sea, and the Beidou navigation system can’t work well. Beidou pseudolite system can improve the performance of Beidou navigation system as a navigation signal transmitter fixed on the ground, the signal of which can improve satellite positioning constellation structure, and improve the system availability reliability and precision. In order to ensure the interoperability and non-correlation of the Beidou pseudolite and the Beidou navigation system, the pseudolite ranging-codes should be selected in the same code space of the satellite ranging-codes and the residual pseudo random code generated by the 2 taps design scheme does not satisfy the performance requirements of the ranging-codes. To solve this issue, a combined design scheme with 3 taps is proposed, and 12 kinds of pseudolite ranging-codes are optimally selected according to the optimum design parameters of ranging-codes. The waveform and correlation of the selected pseudolite ranging-codes are analyzed by MATLAB, the acquisition simulation is carried out by using the new pseudolite ranging-codes. The experimental results show that the new 3-taps based ranging codes design scheme behaves a good balance, correlation and spectral characteristics
3
Content available Application study on cooperative drainage technology for mining-affected pressure relief gas in overlaying adjacent seams
100%
Wang K. , Zang J. , Zhou A. , Gao H.
AGH Journal of Mining and Geoengineering
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2012
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tom Vol. 36, no. 3
385-393
EN
During the mining process of 12# coal seam in Yangquan mine area, gas quantity emitting from overlaying adjacent seams was high and gas concentration in upper corners and return airways of mining faces often exceeded limitation. To solve these problems, through the combination of theoretical study, numerical simulation and on-site observation, the high-low zoning enrichment law of the mining-affected pressure relief gas in overlaying adjacent seams of 12# coal seam was formulated. According to this law, the cooperative drainage technology was proposed, namely arranging the high-located and low-located boreholes to drain the gas respective in high and low enrichment zones. By applying the cooperative drainage technology, the safety production status of mining faces of 12# coal seam in Nanzhuang mine has been significantly ameliorated, advance efficiency, drainage rate and drainage quantity have been improved greatly, carbon emission has been reduced and the environment has been protected, resource utilization has been improved, the service life of the mine will be extended. In a word, good economic, social and environmental benefits have been achieved, meanwhile, a safe, efficient, and sustainable exploitation of the mine has been realized.
PL
Podczas eksploatacji ściany nr 12 w Yangquan zanotowano dużą ilość gazu wydobywającego się z przyległych pokładów węgla. Koncentracja metanu w chodniku nadścianowym bardzo często przekraczała wartości dopuszczalne. Aby rozwiązać te problemy, sformułowano zasadę wysokiego/niskiego odmetanowania dla dekompresji metanu w przyległych do ściany nr 12 pokładach węgla na podstawie symulacji numerycznych oraz obserwacji. W odniesieniu do tej zasady zaproponowano technologię łączonego odprowadzania gazu poprzez otwory wiertnicze zlokalizowane odpowiednio na niższym i wyższym poziomie odpowiednich stref metanowości. Zastosowanie technologii odprowadzania łączonego przyczyniło się do znacznej poprawy bezpieczeństwa produkcji na przodku nr 12 kopalni Nanzhuang, zwiększenia wydajności, prędkości odprowadzania i ilości odprowadzanego gazu, obniżenia emisji dwutlenku węgla oraz lepszej ochrony środowiska, a także lepszego wykorzystania zasobów i wydłużenia okresu eksploatacji kopalni. Krótko mówiąc, uzyskano znaczne korzyści ekonomiczne, społeczne i środowiskowe, przy jednoczesnym zapewnieniu bezpiecznej, wydajnej i zrównoważonej eksploatacji kopalni.
4
Experimental and mathematical investigations on unconfined compressive behaviour of costal soft soil under complicated freezing processes
88%
Wang W. , Li N. , Zhang F. , Zhou A. , Chi S.
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tom 23
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nr 4
EN
In order to properly understand the effect of freezing-thawing circle (FTC) to mechanical behavior of costal soft soil (CSS), unconfined compressive test is conducted. Six kind FTC times are designed from zero to five. The tested data show that: (1) unconfined compressive strength of CCS decreases nonlinearly with more FTC, and the strength after five FTC times becomes about 22% of its original strength without any freezing-thawing experience; (2) stressstrain curves of all unconfined compressive samples can be well fitted by three-parameter hyperbolic model; (3) and relationship between two parameters and FTC times can be fitted by exponent function, while another parameter can be considered as 0.95. Consequently, one composite hyperbolic- exponent empirical formula is established in order to describe freezing-thawing-dependent stress-strain behavior of CSS. Finally, good agreements have been found between tested dada and simulated results
5
Content available Experimental and mathematical investigations on unconfined compressive behaviour of costal soft soil under complicated freezing processes
88%
Wang W. , Li N. , Zhang F. , Zhou A. , Chi S.
|
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tom nr 4
112--116
EN
In order to properly understand the effect of freezing-thawing circle (FTC) to mechanical behavior of costal soft soil (CSS), unconfined compressive test is conducted. Six kind FTC times are designed from zero to five. The tested data show that: (1) unconfined compressive strength of CCS decreases nonlinearly with more FTC, and the strength after five FTC times becomes about 22% of its original strength without any freezing-thawing experience; (2) stressstrain curves of all unconfined compressive samples can be well fitted by three-parameter hyperbolic model; (3) and relationship between two parameters and FTC times can be fitted by exponent function, while another parameter can be considered as 0.95. Consequently, one composite hyperbolic- exponent empirical formula is established in order to describe freezing-thawing-dependent stress-strain behavior of CSS. Finally, good agreements have been found between tested dada and simulated results.
6
Content available Dynamic test and analysis of strength of bamboo curtain plywood based on free vibration modal method
75%
Gu X. , Zhou A. , Zhang R. , Zhou Y. , Wang Z. , Adjei P.
Drewno. Prace Naukowe. Doniesienia. Komunikaty
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2023
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tom 66
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nr 212
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