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Wyszukujesz frazę "Li, T." wg kryterium: Autor


Tytuł:
Regional geographies of land transport networks in the Pearl River Delta mega-region, China: A longitudinal analysis
Autorzy:
Gao, X.
Li, T.
Tematy:
transport network
network efficiency
spatiotemporal evolution
Pearl River Delta
PRD
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Wydawca:
Fundacja Centrum Badań Socjologicznych
Powiązania:
https://bibliotekanauki.pl/articles/2140889.pdf  Link otwiera się w nowym oknie
Opis:
This paper uses network-based efficiency measures to evaluate the efficiency implications of the evolution of the transport network in the Pearl River Delta (PRD) over the period 1988-2008. The network-based efficiency measures consider the relative ease of access between cities in terms of weighted relative travel cost. The results indicate that the spatial patterns of network efficiency are different from ‘core-periphery’ pattern derived from classical accessibility indicators. This implies that there are low network efficiency cities and high network efficiency cities in core and peripheral regions at the same time. In the first stage (1988-1998), the efficiency contour shows a ‘corridor’ pattern along the GuangShen traffic corridor between Guangzhou and Shenzhen in the eastern side of the Pearl estuary; in the following decade (1998-2008), with large-scale infrastructural developments, the spatial pattern has changed from a north-south corridor to an east-west contiguous distribution pattern. By 2008, the mean network efficiency value indicates that the efficiency levels within the PRD as a whole are tending towards optimal levels. We conclude by suggesting ways to promote the urban economic development based on the relationship between the network efficiency and per capita GDP.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Hydrodynamic body shape analysis and their impact on swimming performance
Autorzy:
Li, T-Z.
Zhan, J.-M.
Tematy:
pływanie
biomechanika
metoda VOF
symulacja numeryczna
swimming
biomechanics
swimmer's body shape
VOF method
numerical simulation
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Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Powiązania:
https://bibliotekanauki.pl/articles/306315.pdf  Link otwiera się w nowym oknie
Opis:
This study presents the hydrodynamic characteristics of different adult male swimmer's body shape using computational fluid dynamics method. This simulation strategy is carried out by CFD fluent code with solving the 3D incompressible Navier–Stokes equations using the RNG k-ε turbulence closure. The water free surface is captured by the volume of fluid (VOF) method. A set of full body models, which is based on the anthropometrical characteristics of the most common male swimmers, is created by Computer Aided Industrial Design (CAID) software, Rhinoceros. The analysis of CFD results revealed that swimmer’s body shape has a noticeable effect on the hydrodynamics performances. This explains why male swimmer with an inverted triangle body shape has good hydrodynamic characteristics for competitive swimming.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Band gap properties of periodic tapered beam structure using traveling wave method
Autorzy:
Li, T.
Ma, X.
Zhang, Q.
Wang, Z.
Tematy:
band gap
periodic structure
traveling wave method
Bloch theorem
tapered beam
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Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Powiązania:
https://bibliotekanauki.pl/articles/279452.pdf  Link otwiera się w nowym oknie
Opis:
The wave motion equations of a tapered beam with respect to axial, torsional and flexural deformations are deduced including the transmission and waveguide equations. Combining the force equilibrium and displacement coordination conditions at the junction, we obtain the relation between the wavenumber and frequency, and the band gap properties of periodic tapered beam structures by the Bloch theorem. The modeling accuracy and efficiency of the traveling wave method are verified by the finite element method. The band gap properties of periodic tampered and uniform beam structures are analyzed and compared for the same materials and lengths as well as the same volumes.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Rapid estimation of environmental radioactivity surrounding Xiangshan uranium deposits, Jiangxi province, Eastern China
Autorzy:
Gan, N.
Cen, K.
Ye, R.
Li, T.
Tematy:
gamma dose rate
indoor radon
water radon
cesium
annual effective dose
Xiangshan uranium deposit
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Wydawca:
Instytut Chemii i Techniki Jądrowej
Powiązania:
https://bibliotekanauki.pl/articles/148900.pdf  Link otwiera się w nowym oknie
Opis:
The surveys of terrestrial gamma dose rate, radon concentration indoor and in water and specific activity of radionuclides of soil were carried out in 14 villages and a town in Xiangshan uranium deposit and surrounding area, Jiangxi province, Eastern China, in 2017–2018, using a scintillator dosemeter, an ionization chamber and a high-purity germanium gamma spectrometer to study radiation status in these places after remediation. A radioactive hot spot was discovered in a village near the mining office, where specific activity of 238U, 226Ra, 232Th and 137Cs of soil was as high as 1433 ± 76 Bq/kg, 1210 ± 62 Bq/kg, 236 ± 13 Bq/kg and 17 ± 1.1 Bq/kg, respectively. The dose rate on a waste rock heap was about 2423 nGy/h. Approximately 50% of the houses in a village near the uranium mining site had radon concentrations that exceeded 160 Bq/m3 . There was a significant positive correlation between indoor radon concentration and outdoor gamma dose rate (R2 = 0.7876). The abnormal radon concentration was observed in a rising spring sample providing residents with tap water up to 127.1 Bq/l. Four tap water samples and three of five well water samples exceeded the limit of radon concentration of drinking water in China (11.1 Bq/l). The mean annual effective doses from gamma dose rate data were 0.86 mSv/y and 1.13 mSv/y for indoor radon. The study shows that there are some radioactively contaminated places surrounding the Xiangshan uranium mine. The local outdoor dose rate averages may be used to estimate local indoor radon concentrations.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Matched-field Source Localization with a Mobile Short Horizontal Linear Array in Offshore Shallow Water
Autorzy:
Zhao, D.
Huang, Z.
Su, S.
Li, T.
Tematy:
passive source localization
matched-field processing
inter-position processing
short horizontal array
shallow water
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Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:
https://bibliotekanauki.pl/articles/177986.pdf  Link otwiera się w nowym oknie
Opis:
Passive source localization in shallow water has always been an important and challenging problem. Implementing scientific research, surveying, and monitoring using a short, less than ten meter long, horizontal linear array has received considerable attention in the recent years. The short array can be conveniently placed on autonomous underwater vehicles and deployed for adaptive spatial sampling. However, it is usually difficult to obtain a sufficient spatial gain for localizing long-range sources due to its limited physical size. To address this problem, a localization approach is proposed which is based on matched-field processing of the likelihood of the passive source localization in shallow water, as well as inter-position processing for the improved localization performance and the enhanced stability of the estimation process. The ability of the proposed approach is examined through the two-dimensional synthetic test cases which involves ocean environmental mismatch and position errors of the short array. The presented results illustrate the localization performance for various source locations at different signal- to-noise ratios and demonstrate the build up over time of the positional parameters of the estimated source as the short array moves at a low speed along a straight line at a certain depth.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effects of selenium on the growth and photosynthetic characteristics of flue-cured tobacco (Nicotiana tabacum L.)
Autorzy:
Jiang, C.
Zu, C.
Shen, J.
Shao, F.
Li, T.
Tematy:
selenium
growth
photosynthesis
tobacco plant
Nicotiana tabacum
carboxylation efficiency
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Wydawca:
Polskie Towarzystwo Botaniczne
Powiązania:
https://bibliotekanauki.pl/articles/57536.pdf  Link otwiera się w nowym oknie
Opis:
The objective of this study was to investigate the effect of Selenium (Se) supply (0, 3, 6, 12, 24 mg kg−1) on the growth, photosynthetic characteristics, Se accumulation and distribution of flue-cured tobacco (Nicotiana tabacum L.). Results showed that low-dose Se treatments (≤6 mg kg−1) stimulated plant growth but high-dose Se treatments (≥12 mg kg−1) hindered plant growth. Optimal Se dose (6 mg kg−1) stimulated plant growth by reducing MDA content and improving photosynthetic capability. However, excess Se (24 mg kg−1) increased MDA content by 28%, decreased net photosynthetic rate and carboxylation efficiency by 34% and 39%, respectively. The Se concentration in the roots, stems, and leaves of the tobacco plants significantly increased with increasing Se application. A linear correlation (R = 0.95, P < 0.01) was observed between Se level and tobacco plant tissue Se concentration. This correlation indicated that the tobacco plant tissues were not saturated within the concentration range tested. The pattern of total Se concentration in the tobacco plant tissues followed the order root > leaf > stem. The Se concentration in the roots was 3.17 and 7.57 times higher than that in the leaves and stems, respectively, after treatment with 24 mg kg−1 Se. In conclusion, the present study suggested that optimal Se dose (6 mg kg−1) improved the plant growth mainly by enhancing photosynthesis, stomatal conductance, carboxylation efficiency and Rubisco content in the flue-cured tobacco leaves. However, the inhibition of excess Se on tobacco growth might be due to high accumulation of Se in roots and the damage of photosynthesis in leaves.
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Traffic fatalities prediction based on support vector machine
Autorzy:
Li, T.
Yang, Y.
Wang, Y.
Chen, C.
Yao, J.
Tematy:
traffic accident
support vector machine
SVM
particle swarm optimization (PSO)
PSO
prediction model
optimal parameters
wypadek drogowy
Particle Swarm Optimization
model prognostyczny
optymalne parametry
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Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:
https://bibliotekanauki.pl/articles/223743.pdf  Link otwiera się w nowym oknie
Opis:
To effectively predict traffic fatalities and promote the friendly development of transportation, a prediction model of traffic fatalities is established based on support vector machine (SVM). As the prediction accuracy of SVM largely depends on the selection of parameters, Particle Swarm Optimization (PSO) is introduced to find the optimal parameters. In this paper, small sample and nonlinear data are used to predict fatalities of traffic accident. Traffic accident statistics data of China from 1981 to 2012 are chosen as experimental data. The input variables for predicting accident are highway mileage, vehicle number and population size while the output variables are traffic fatality. To verify the validity of the proposed prediction method, the back-propagation neural network (BPNN) prediction model and SVM prediction model are also used to predict the traffic fatalities. The results show that compared with BPNN prediction model and SVM model, the prediction model of traffic fatalities based on PSO-SVM has higher prediction precision and smaller errors. The model can be more effective to forecast the traffic fatalities. And the method using particle swarm optimization algorithm for parameter optimization of SVM is feasible and effective. In addition, this method avoids overcomes the problem of “over learning” in neural network training progress.
Dostawca treści:
Biblioteka Nauki
Artykuł

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