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Wyszukujesz frazę "Li, Cheng" wg kryterium: Autor


Tytuł:
Fillet effect on the bending crashworthiness of thin-walled square tubes
Autorzy:
Xie, Zhongyou
Zhao, Zhixian
Zhou, Xiuneng
Li, Cheng
Powiązania:
https://bibliotekanauki.pl/articles/2086940.pdf
Data publikacji:
2022
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
thin-walled square tubes
bending crashworthiness
fillet effect
three-point bending
finite element analysis
Opis:
Filleting four corners of square tubes is suggested to reduce the peak force and improve energy absorbing performance. Three-point bending tests are conducted to investigate fillet radius effects employing an ABAQUS explicit code. Three cases characterized by the ratio of width to thickness are considered. Fillet greatly reduces the maximum forces compared with square cross-sections, and the normalized maximum forces decrease with increasing wall thickness when the fillet radius is larger. Additionally, the fillet dramatically improves SEA (Specific Energy Absorption). The normalized CFE (Crash Load Efficiency) significantly exceeds that of the square ones, and the normalized CLEs are almost identical with the increasing fillet radius.
Źródło:
Journal of Theoretical and Applied Mechanics; 2022, 60, 1; 103--111
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Collapse modes of concrete reinforced square bridge piers under vehicle collision
Autorzy:
Zhou, Xiuneng
Xie, Zhongyou
Zhao, Zhixian
Li, Cheng
Powiązania:
https://bibliotekanauki.pl/articles/2086980.pdf
Data publikacji:
2022
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
RC square pier
collapse mode
vehicle collision
numerical simulation
Opis:
In the field of engineering protection, there is a structural disaster named heavy vehicles impacting column structures. When a heavy truck collides with a reinforced concrete (RC) column at a high velocity, a large impact force generated makes perhaps the column fail and even collapse. Therefore, it is necessary to study the dynamic characteristics during such a disaster, which can provide some reference for structural design, optimization and protection. The RC column impacted by a vehicle could be simplified as a beam fixed at the bottom loaded by a concentrated force, whose deformation is controlled by shearing and bending. In the present work, the ultimate static forces corresponding to shearing and bending collapse are proposed based on theoretical analyses. The model validation is performed using the finite element approach and the theoretical analytical results are in good agreement with the finite element simulation results, which validates the present analytical model. Three cases are simulated by utilizing finite element code ABAQUS, which reveals that the approximate plateau collapse force keeps a long stage beyond the peak failure one. In addition, three collapse modes are observed based on the static force and deformation analysis, validating the present framework which can be used for routine pier design. The work can be extended to estimate collapse modes of building columns under a vehicle collision.
Źródło:
Journal of Theoretical and Applied Mechanics; 2022, 60, 3; 375--384
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Prediction of PM2.5 hourly concentrations in Beijing based on machine learning algorithm and ground-based LiDAR
Autorzy:
Fang, Zhiyuan
Yang, Hao
Li, Cheng
Cheng, Liangliang
Zhao, Ming
Xie, Chenbo
Powiązania:
https://bibliotekanauki.pl/articles/2073773.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
PM2.5
LiDAR
machine learning
air pollution monitoring
Opis:
The prediction of PM2.5 is important for environmental forecasting and air pollution control. In this study, four machine learning methods, ground-based LiDAR data and meteorological data were used to predict the ground-level PM2.5 concentrations in Beijing. Among the four methods, the random forest (RF) method was the most effective in predicting ground-level PM2.5 concentrations. Compared with BP neural network, support vector machine (SVM), and various linear fitting methods, the accuracy of the RF method was superior by 10%. The method can describe the spatial and temporal variation in PM2.5 concentrations under different meteorological conditions, with low root mean square error (RMSE) and mean square deviation (MD), and the consistency index (IA) reached 99.69%. Under different weather conditions, the hourly variation in PM2.5 concentrations has a good descriptive ability. In this paper, we analyzed the weights of input variables in the RF method, constructed a pollution case to correspond to the relationship between input variables and PM2.5, and analyzed the sources of pollutants via HYSPLIT backward trajectory. This method can study the interaction between PM2.5 and air pollution variables, and provide new ideas for preventing and forecasting air pollution.
Źródło:
Archives of Environmental Protection; 2021, 47, 3; 98--107
2083-4772
2083-4810
Pojawia się w:
Archives of Environmental Protection
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigations on the Spin-Hamiltonian Parameters and Local Structure of the Orthorhombic $Cu^{2+}$ Center in $PbTiO_3$ Crystal
Autorzy:
Chao-Ying, Li
Li-Bin, Cheng
Xue-Mei, Zheng
Powiązania:
https://bibliotekanauki.pl/articles/1400511.pdf
Data publikacji:
2015-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
76.30.Fc
75.10.Dg
71.70.Ch
Opis:
The spin-Hamiltonian parameters (the g factors $g_{i}$ and the hyperfine structure constants $A_{i}$, i = x, y, z) and local structure of the $Cu^{2+}$ center in $PbTiO_{3}$ are theoretically studied by using the perturbation formulae of these parameters for a $3d^{9}$ ion in an orthorhombically elongated octahedra. The orthorhombic center is attributed to $Cu^{2+}$ occupying the host $Ti^{4+}$ site associated with a nearest-neighbouring oxygen vacancy $V_{O}$ along the c-axis, and the impurity $Cu^{2+}$ off-center displacement $\Delta Z_{L}$ ( ≈0.18 Å) is smaller than that of the host $Ti^{4+}$ site ($\Delta Z_{H}$≈ 0.3 Å). Meanwhile, the planar $Cu^{2+}-O^{2-}$ bonds are found to experience the relative variation ΔR ( ≈ 0.098 Å) along the a- and b-axes, respectively, due to the Jahn-Teller effect and the size mismatching substitution of $Ti^{4+}$ by $Cu^{2+}$. The theoretical spin-Hamiltonian parameters based on the above defect structure agree well with the observed values.
Źródło:
Acta Physica Polonica A; 2015, 127, 6; 1671-1675
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ponad granicami
Autorzy:
Cheng, Li-Rong Lilly
Powiązania:
https://bibliotekanauki.pl/articles/690460.pdf
Data publikacji:
2016
Wydawca:
Uniwersytet Marii Curie-Skłodowskiej. Wydawnictwo Uniwersytetu Marii Curie-Skłodowskiej
Opis:
The article doesn't have Abstract.
Artykuł nie zawiera streszczenia w jezyku polskim.
Źródło:
Annales Universitatis Mariae Curie-Sklodowska, sectio N – Educatio Nova; 2016, 1
2451-0491
Pojawia się w:
Annales Universitatis Mariae Curie-Sklodowska, sectio N – Educatio Nova
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Classifications and existence of positive solutions of a higher order nonlinear difference equation
Autorzy:
Li, Wan-Tong
Cheng, Sui
Powiązania:
https://bibliotekanauki.pl/articles/965788.pdf
Data publikacji:
2000
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Tematy:
sublinear function
nonlinear difference equation
superlinear function
eventually positive solution
existence theorem
Opis:
A classification scheme for the eventually positive solutions of a class of higher order nonlinear difference equations is given in terms of their asymptotic magnitudes, and necessary as well as sufficient conditions for the existence of such solutions are provided.
Źródło:
Colloquium Mathematicum; 2000, 83, 1; 137-153
0010-1354
Pojawia się w:
Colloquium Mathematicum
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Transverse energy propagation and interference of elliptical Gaussian beams
Autorzy:
Li, Jin
Tan, Shuang-Cheng
Powiązania:
https://bibliotekanauki.pl/articles/27310096.pdf
Data publikacji:
2023
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
elliptical Gaussian beam
transverse energy flux
interference of EGBs
Opis:
Elliptical Gaussian beam (EGB) has many different physical properties from circular Gaussian beam. In this paper, the transverse energy flux and intensity of one and two coherent EGBs are studied. In our simulation, the transverse energy flux and intensity varying with waist ratio are discussed in detail. It has been found that through increasing the waist ratio, the transverse energy flux after interference would be strengthened significantly. Although the transverse energy flux is much weaker than the longitudinal energy flux, its signal to noise ratio has been verified to be strong enough for detection. Our derivations are still reasonable for another simulation with general experimental parameters. The simulation results are considered to be helpful for some physical experiments using the transverse energy flux of Gaussian beam, such as an important application in electromagnetic response produced by interaction of high-frequency gravitational waves.
Źródło:
Optica Applicata; 2023, 53, 2; 249--260
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dynamic response of a base-isolated concrete rectangular liquid-storage structure under large amplitude sloshing
Dynamiczna odpowiedź prostokątnej struktury magazynowania substancji ciekłych z wykorzystaniem betonu izolacyjnego
Autorzy:
Cheng, X.
Li, D.
Li, P.
Zhang, X.
Li, G.
Powiązania:
https://bibliotekanauki.pl/articles/230249.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
chlupotanie cieczy
amplituda duża
trzęsienie ziemi
struktura prostokątna
substancja ciekła
magazynowanie
nieliniowość
odpowiedź dynamiczna
liquid sloshing
large amplitude
earthquake
rectangular structure
liquid substance
storage
nonlinearity
dynamic response
Opis:
Considering concrete nonlinearity, the wave height limit between small and large amplitude sloshing is defined based on the Bernoulli equation. Based on Navier-Stokes equations, the mathematical model of large amplitude sloshing is established for a Concrete Rectangle Liquid-Storage Structure (CRLSS). The results show that the seismic response of a CRLSS increases with the increase of seismic intensity. Under different seismic fortification intensities, the change in trend of wave height, wallboard displacement, and stress are the same, but the amplitudes are not. The areas of stress concentration appear mainly at the connections between the wallboards, and the connections between the wallboard and the bottom.
Gdy amplituda chlupotania cieczy jest zbliżona do częstotliwości drgań struktury magazynowania substancji ciekłych (CRLSS), wówczas osiągamy rezonans i możemy zaobserwować silne zjawisko nieliniowe. Szkoda jest znacznie większa niż chlupotanie o małej amplitudzie. Obecnie brak jest odpowiedniego raportu na temat badań dynamicznej odpowiedzi struktury magazynowania substancji ciekłych z wykorzystaniem betonu izolacyjnego (CRLSS) z chlupotaniem o dużej amplitudzie, a wpływ materiałów betonowych nie jest brany pod uwagę. W związku z tym, w niniejszej pracy, w oparciu o równanie Bernoulliego, otrzymano ograniczone wysokości fali o dużej amplitudzie chlupotania oraz małej amplitudzie chlupotania. Na podstawie równań Naviera-Stokesa ustanowiono matematyczny model chlupotania o dużej amplitudzie i zbadano odpowiedź sejsmiczną CRLSS podczas chlupotania o dużej amplitudzie. Rozważając równanie Bernoulliego i zadowalający stan, chlupotanie substancji ciekłej jest liniowe, a nieliniowy kwadratowy człon jest lekceważony. W stałym i płynnym interfejsie, struktura magazynowania substancji ciekłych spełnia warunki ciągłości przemieszczania i równowagi siły oddziaływań. Właściwość mechaniczna gumowego zabezpieczenia izolacyjnego została opisana w oparciu o konstytutywną relacje modelu Mooney-Rivlin.
Źródło:
Archives of Civil Engineering; 2017, 63, 1; 33-45
1230-2945
Pojawia się w:
Archives of Civil Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Pentagon na gorącej linii z Pekinem : Chiny to potencjalnie najpoważniejszy przeciwnik USA : amerykański sekretarz obrony próbuje zmniejszyć ryzyko napięć
Autorzy:
Gillert, Piotr.
Lu Yiyi.
Cheng Li.
Powiązania:
Rzeczpospolita 2007, nr 259, s. A12
Data publikacji:
2007
Opis:
Zawiera wypow. dr Yiyi Lu, eksperta instytutu Chatham House w Londynie oraz prof. Li Cheng, eksperta Brookings Institution w Waszyngtonie.
Fot.
Dostawca treści:
Bibliografia CBW
Artykuł
Tytuł:
Neuro-adaptive cooperative control for high-order nonlinear multi-agent systems with uncertainties
Autorzy:
Peng, Cheng
Zhang, Anguo
Li, Junyu
Powiązania:
https://bibliotekanauki.pl/articles/2055174.pdf
Data publikacji:
2021
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
multiagent system
radial basis function
RBF neural network
sliding mode control
cooperative control
system wieloagentowy
radialna funkcja bazowa
sieć neuronowa RBF
sterowanie ślizgowe
Opis:
The consensus problem for a class of high-order nonlinear multi-agent systems (MASs) with external disturbance and system uncertainty is studied. We design an online-update radial basis function (RBF) neural network based distributed adaptive control protocol, where the sliding model control method is also applied to eliminate the influence of the external disturbance and system uncertainty. System consensus is verified by using the Lyapunov stability theorem, and sufficient conditions for cooperative uniform ultimately boundedness (CUUB) are also derived. Two simulation examples demonstrate the effectiveness of the proposed method for both homogeneous and heterogeneous MASs.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2021, 31, 4; 635--645
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigation on a quasi-zero-stiffness vibration isolator under random excitation
Autorzy:
Wang, Y.
Li, S.
Cheng, C.
Powiązania:
https://bibliotekanauki.pl/articles/281608.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
vibration isolator
quasi-zero-stiffness
random excitation
dynamic analysis
performance analysis
Opis:
The dynamic response and isolation performance of a Quasi-Zero-Stiffness (QZS) vibration isolator using inclined springs as negative stiffness correctors under random excitation are presented in this paper. The probabilistic linearization method is employed to determine the dynamic response of the QZS vibration isolator and compared with the exact solution based on the Fokker-Planck-Kolmogorov (FPK) equation and the equivalent linearization method. Two performance indexes (Mean Square Relative Displacement (MSRD) and Mean Square Acceleration (MSA)) are considered to evaluate the isolation performance of the QZS vibration isolator under random excitation and compared with the equivalent linear vibration isolator. The results show that the MSRD of the QZS vibration isolator is always lower than the equivalent linear vibration isolator, while the MSA of the QZS vibration isolator can be larger or lower than the equivalent linear vibration isolator based on the values of damping ratio and spectral density of the random excitation
Źródło:
Journal of Theoretical and Applied Mechanics; 2016, 54, 2; 621-632
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Partitioning of solar radiation in Arctic sea ice during melt season
Autorzy:
Lu, P.
Cheng, B.
Lepparanta, M.
Li, Z.
Powiązania:
https://bibliotekanauki.pl/articles/48057.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
solar radiation
partitioning
Arctic Sea
sea ice
melt season
solar energy
energy absorption
mass balance
spectral irradiance
numerical modelling
Źródło:
Oceanologia; 2018, 60, 4
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dynamic evolution of mixed circular edge-screw dislocations
Autorzy:
Gao, P.
Li, J.
Cheng, K.
Duan, M.
Powiązania:
https://bibliotekanauki.pl/articles/173359.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
mixed circular edge-screw dislocations
optical vortex
circular edge dislocations
atmospheric turbulence
Opis:
Based on the extended Huygens–Fresnel principle, the analytical expressions for the cross-spectral density function of mixed circular edge-screw dislocations beams propagating through atmospheric turbulence have been derived, and used to study the dynamic evolution of mixed circular edge-screw dislocations in free space and atmospheric turbulence. It is shown that the radius of circular edge dislocations increases with increasing propagation distance, and both the positions of the optical vortex and the center of circular edge dislocations are located at the point (0, 0) when mixed circular edge-screw dislocations propagate in free space. When mixed circular edge-screw dislocations propagate in the atmospheric turbulence, the position of optical vortices varies with increasing propagation distance, the circular edge dislocation evolves into a pair of optical vortices with the opposite topological charge ±1, and the pair of optical vortices will annihilate as soon as the propagation distance becomes large enough.
Źródło:
Optica Applicata; 2017, 47, 3; 471-481
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synthesis of antibacterial polyurethane film and its properties
Autorzy:
Lin, Zhao
Yunyun, Li
Bin, Cheng
Yu, Chen
Powiązania:
https://bibliotekanauki.pl/articles/779374.pdf
Data publikacji:
2020
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
polyurethane
Ag nanoparticles
antibacterial
composite film
Opis:
Polyurethane (PU) is a polymer widely used in the biomedical field with excellent mechanical properties and good biocompatibility. However, it usually exhibits poor antibacterial properties for practical applications. Efforts are needed to improve the antibacterial activities of PU films for broader application prospect and added application values. In the present work, two PU films, TDI-P(E-co-T) and TDI-N-100-P(E-co-T), were prepared. Silver nanoparticles (AgNPs) were composited into the TDI-N-100-P(E-co-T) film for better mechanical properties and antibacterial activities, and resultant PU/AgNPs composite film was systematically characterized and studied. The as-prepared PU/AgNPs composite film exhibits much better antibacterial properties than the traditional PU membrane, exhibiting broader application prospect.
Źródło:
Polish Journal of Chemical Technology; 2020, 22, 2; 50-55
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synergism of octane phenol polyoxyethylene-10 and oleic acid in apatite flotation
Autorzy:
Cheng, R.
Li, C.
Liu, X.
Deng, S.
Powiązania:
https://bibliotekanauki.pl/articles/110793.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
octane phenol polyoxyethylene-10
synergistic effect
flotation
apatite
Opis:
The addition of octane phenol polyoxyethylene-10 (OP-10) to oleic acid via a reagent-combination technology was carried out and it was shown that OP-10 exhibited synergistic effects in the flotation performance of oleic acid. Single-mineral flotation tests, zeta-potential measurements, total-organic-carbon determination, and scale-up of continuous tests using raw ore were also carried out. Single-mineral flotation tests showed that OP-10 exhibited virtually no collecting performance for apatite, but it improved the flotation performance of oleic acid following its addition to oleic acid in small amounts at low temperature. Zeta-potential measurements and total-organic-carbon determination results indicated that the addition of 2.5% OP-10 to oleic acid increased the absolute value of the apatite surface potential and improved adsorption of oleic acid on the apatite surface at low temperature. A scale-up of the continuous test showed that application of OP-10 with industrial fatty acids led to good synergistic effects and contributed to effective separation of phosphate ore.
Źródło:
Physicochemical Problems of Mineral Processing; 2017, 53, 2; 1214-1227
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł

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