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Wyszukujesz frazę "Li, Guo" wg kryterium: Autor


Tytuł:
Effects of U-shaped two-step throttling groove parameters on cavitation erosion characteristics
Autorzy:
Jia, Wenhua
Liu, Yanyan
Yin, Chenbo
Li, Guo
Zhu, Dasheng
Ding, Shen
Powiązania:
https://bibliotekanauki.pl/articles/2055063.pdf
Data publikacji:
2021
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
avitation erosion
throttling groove
distribution coefficient
Opis:
Throttling usually occurs when a fluid passes through an orifice, sometimes even severe cav- itation erosion may occur. In this study, the equation for the cavitation index of a throttling valve was proposed and the cavitation erosion area in the throttle valve was found to change its position with the orifice opening (X). Cavitation features of singular and two-port se- ries throttling grooves were characterized by defining cavitation indexes σ1and σ2, because the cavitation index-σ can determine the occurrence and intensity of cavitation. Then the indexes σ1 and σ2 included internal geometric parameters and external pressure boundaries were obtained, and cavitation indexes curves σ1-X and σ2-X were also plotted. From the curves of the cavitation index, it was observed that cavitation concentration section also would transfer with opening X changes in the U-shaped groove. The depth of the U-shaped groove had a more evident impact on cavitation, whereas the effect of width on cavitation erosion was not so obvious. The intensity of cavitation erosion when the fluid flowed into the orifice section of the U-shaped groove was always larger than that when the fluid flowed away.
Źródło:
Journal of Theoretical and Applied Mechanics; 2021, 59, 4; 529--538
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
First-Principles Calculations for Structural, Elastic, Electronic and Thermodynamic Properties of $HfZn_{2}$ under Pressure
Autorzy:
Li, Guo-Jun
Shi, Lan-Ting
Hu, Cui-E
Cheng, Yan
Ji, Guang-Fu
Powiązania:
https://bibliotekanauki.pl/articles/1398192.pdf
Data publikacji:
2018-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
C15 Laves-phase
elastic properties
electronic structure
vibrational properties
quasi-harmonic approximation
Opis:
By using density functional theory within the Perdew-Burke-Ernzerhof generalized gradient approximation implemented in the VASP code, we study the structural, elastic, electronic, and thermodynamic properties of C15 Laves-phase compound $HfZn_{2}$. Comparing the lattice constants calculated from the Perdew-Burke-Ernzerhof generalized gradient approximation and local density approximation, we find that the former is in better agreement with the experimental data. The elastic constants of $HfZn_{2}$ calculated by strain-stress method indicate that they keep stable up to 100 GPa. The bonding characteristics are discussed by analyzing the energy band structure, charge density distribution and charge density difference. Phonon dispersion curves and phonon density of states of HfZn_{2} at the different pressure are predicted for the first time. In addition, there is no imaginary frequency in the phonon band at different pressure, which also shows that $HfZn_{2}$ is stable up to 100 GPa. Vibrational models are also illustrated based on phonon and group theory. The thermodynamic properties under high temperature and high pressure are calculated by different thermodynamic models. The heat capacity at constant pressure and low temperature calculated by quasi-harmonic approximation is more close to the measurement than that calculated by quasi-harmonic Debye models.
Źródło:
Acta Physica Polonica A; 2018, 133, 5; 1299-1306
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Counterion effects on the alkali dissolution mechanism of quartz
Autorzy:
Yao, Yu-yun
Tang, Yun
Yang, Yong
Li, Guo-hui
Wu, Bo
Dai, Wen-zhi
Powiązania:
https://bibliotekanauki.pl/articles/2200337.pdf
Data publikacji:
2023
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
quartz
counterion
quantum chemistry
hydrolysis
mechanism
Opis:
In gold ore, quartz plays an important role in mineral formation by acting as the follower. Understanding counterion release, transport, and deposition in alkali solution is a prerequisite for evaluating the potential role of gold separate from quartz deposits in pretreatment. In this work, the aggregation, retention, and release of counterion in alkali solution media were investigated by kinetic research and pure mineral experiments, the correlation and mechanism of these processes were revealed by combining geochemical theory, interaction energy calculation, and quantum chemistry. The results showed that the retention and release of counterion were closely related to the dissolution and corrosion rate of quartz. The NH4+ and Fe2+ with higher mineral affinity reduced the quartz stability, and the dispersion stability and mobility of the quartz were greatly improved by an alkaline substance due to the enhancement of steric hindrance effects. Quantum chemical calculation results show that ammonium ion promotes the dissolution of quartz stronger than ferrous ion, which is mainly reflected in reducing the activation energy required for the formation of transition state (TS1), which can be verified by kinetic calculation. These findings provide essential insight into the extraction of gold coated by quartz as well as a vital reference for the experiment of gold-loaded quartz leaching in mineral processing.
Źródło:
Physicochemical Problems of Mineral Processing; 2023, 59, 1; art. no. 160038
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A modified model of residual strength prediction for metal plates with through-thickness cracks
Autorzy:
Li, Yanping
Wang, Jianjun
Guo, Weiguo
Guo, Jin
Powiązania:
https://bibliotekanauki.pl/articles/281643.pdf
Data publikacji:
2019
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
residual strength
damage degree factor
crack
multiple site damage
Opis:
A new model, accurate and easy-to-apply, has been proposed to predict the residual strength for metal plates intact or with different damage degrees. In this model, we introduced the damage degree factor (DDF) to quantify the initial damage condition of a plate. The middle crack tension (M(T)) tests and multiple site damage (MSD) tension tests were performed on plate specimens in aluminum alloy LY12-CZ and 2524-T3, respectively. For various damage degrees, the predicted results of this new model showed an improved correlation with test results compared to the net section yield criterion, K-apparent criterion and Duong’s method.
Źródło:
Journal of Theoretical and Applied Mechanics; 2019, 57, 3; 537-547
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Preparation and Performance of CL-20-based Ultraviolet-curable High-explosive Ink and Its Application in Rigid Explosive Networks by Direct Ink Writing
Autorzy:
Li, Rui
Li, Weibing
Guo, Xiaode
Liang, Li
Wang, Yajun
Li, Weibin
Powiązania:
https://bibliotekanauki.pl/articles/27787838.pdf
Data publikacji:
2021
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
multi-point initiation explosive network
UV-curability highexplosive ink
direct ink writing/printing
initiation synchronicity error
precise press-loading charge
Opis:
To improve the groove charge consistency and density and to reduce the initiation synchronicity error of a rigid multi-point initiation explosive network, a CL-20-based ultraviolet (UV)-curable high-explosive ink, comprising 42 wt.% sub-micron CL-20, a 55.4 wt.% binder system (including 2.0 wt.% NC and 53.4 wt.% butyl acetate), and 2.6 wt.% UV-curable resin, based on direct ink writing (DIW) technology, was prepared. The properties of the composite sample deposited via DIW were characterized. The results indicated that the sample had good uniformity, with few defects, and a critical detonation size of around 1.5×0.283 mm. A six-point initiation explosive network was designed for the integration of DIW technology and precise press-loading of the charge. The network featured six pre-pressed booster pellets with the same charge density (ρ0 = 1.89 g·cm−3, 95.8% of theoretical maximum density) as the output end charges, and a groove channel charged by DIW and press-loading. This procedure increased the density of the booster charge in the groove channels to 1.890 g·cm−3, effectively improved the consistency of the charge density between the groove channels and the output ends and lowered the initiation synchronicity error of the network to 62 ns. The network can initiate a jetting projectile charge (JPC) with good shape and small lateral offset, implying that the network initiation capability and synchronization meet the operational requirements of JPC shaped charges.
Źródło:
Central European Journal of Energetic Materials; 2021, 18, 1; 86--111
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research on emergency DC power support coordinated control for hybrid multi-infeed HVDC system
Autorzy:
Li, Congshan
Li, Yikai
Guo, Jian
He, Ping
Powiązania:
https://bibliotekanauki.pl/articles/140422.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
additional controllers
coordinated control
EDCPS
hybrid multi-infeed HVDC system
HVDC
Opis:
Based on the respective characteristics of line-commutated converter highvoltage direct current (LCC-HVDC) and voltage-source converter high voltage direct current (VSC-HVDC), two additional emergency DC power support (EDCPS) controllers are designed, respectively. In addition a coordinated control strategy based on a hybrid multi-infeed HVDC system for EDCPS is proposed. Considering the difference in system recovery between LCC-HVDC and VSC-HVDC in EDCPS, according to the magnitude of the amount of potential power loss, the LCC-HVDC and VSC-HVDC priority issues of boosting power for EDCPS are discussed in detail. Finally, a hybrid three-infeed HVDC that consists of two parallel LCC-HVDCs and one VSC-HVDC that is built in PSCAD/EMTDC are simulated. The effectiveness of the proposed approach is verified based on this hybrid three-infeed HVDC system.
Źródło:
Archives of Electrical Engineering; 2020, 69, 1; 5-21
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of out-of-plane free vibration of single damaged curved beam based on precise algorithm of structural mechanics
Autorzy:
Li, Xiaofei
Pan, Zhouyang
Guo, Hainan
Powiązania:
https://bibliotekanauki.pl/articles/2200899.pdf
Data publikacji:
2023
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
out-of-plane curved beam
damaged
stiffness matrix
free vibration
Opis:
Based on a dynamic discrete model of an out-of-plane curved beam with a constant cur- vature, eigen-properties of the spatial curved beam structure in undamaged and damaged configurations are considered in this paper. In the literature, based on the equivalent sec- tion reduction method, a distributed damage modeling method is proposed. Accoding to Euler-Bernoulli beam theory, the stiffness matrix of shear, bending and torsion coupling is derived. Combined with the lumped mass matrix and the characteristic equation of the multi degree of freedom system, natural frequencies of the undamaged and damaged structures are calculated.
Źródło:
Journal of Theoretical and Applied Mechanics; 2023, 61, 2; 407--414
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The synergistic effect of boric acid and ammonium polyphosphate on the thermal degradation and flammability of pine-needles
Autorzy:
Li, L.
Hu, H.
Guo, C.
Powiązania:
https://bibliotekanauki.pl/articles/52633.pdf
Data publikacji:
2014
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Technologii Drewna
Tematy:
synergistic effect
boric acid
ammonium polyphosphate
thermal degradation
flammability
pine needle
needle
pyrolysis
temperature
flame retardant
Opis:
The synergistic effect of ammonium polyphosphate (APP) and boric acid (BA) on the flame retardancy and thermal degradation of pine needles was investigated. Thermogravimetric analysis (TGA) showed that the presence of an ammoniumpolyphosphate and boric acid system increased the char residue and decreased the pyrolysis temperature of the pine needles. The derivative thermogravimetric analysis (DTG) showed that the ammonium polyphosphate and boric acid had shifted the degradation peaks of the pine needles to lower temperatures. The cone calorimetry test results showed that the values of HRR, THR, SPR, TSP and the mass loss (%) of the pine needles treated with ammonium polyphosphate and boric acid (APP/BA = 3/2)were significantly lower than the other samples. Therefore, the APP and BA system had a better effect on the pine needles overall than the APP alone.
Źródło:
Drewno. Prace Naukowe. Doniesienia. Komunikaty; 2014, 57, 193
1644-3985
Pojawia się w:
Drewno. Prace Naukowe. Doniesienia. Komunikaty
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Biomechanical and fluid flowing characteristics of intervertebral disc of lumbar spine predicted by poroelastic finite element method
Autorzy:
Guo, L.-X
Li, R.
Zhang, M.
Powiązania:
https://bibliotekanauki.pl/articles/307246.pdf
Data publikacji:
2016
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
kręgosłup lędźwiowy
poroelastyczność
FEM
lumbar spine
poroelastic finite element model
intermittent compressive load
permeability of cartilage endplate
Opis:
Purpose: This study is to reveal the deformation of intervertebral disc (IVD), the stress distribution of solid phase and liquid phase, the variation of fluid flux and flow velocity in lumbar spine and the influence of different permeability parameters on them under intermittent compressive loading. Methods: A poroelastic FEM of L4-L5 is assigned with different permeability parameters to analyze the deformation, stress distribution and fluid convection under intermittent compressive loads. Results: The results show that the pore pressure of IVD decreases with time, but the effective stress increases under intermittent compressive loads. The axial and radial strain will increase and fluid loss will recover at a more rapid rate if the permeability of endplate increases during unloading period. The velocity vectors show that most of the liquid in the disc flows into vertebrae through endplates and only a small quantity of liquid flows through the annulus fibrosus at the loading step, however, at the unloading step, almost all the liquid flowing into IVD is through the endplates. Conclusions: The changing rate of pore pressure and effective stresses of nucleus pulposus and annulus fibrosus with higher permeability is smaller than that with smaller permeability. The degenerated endplate (with low permeability) yields high flow velocity decreasing gradient, which might impede liquid inflowing/outflowing smoothly through the endplates. The fluid flowing velocity in loading phase is faster than that in unloading phase, so a short resting time can relieve fatigue, but could not recover to the original liquid condition in IVDs.
Źródło:
Acta of Bioengineering and Biomechanics; 2016, 18, 2; 19-29
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study of a new type of Flettner rotor in merchant ships
Autorzy:
Li, Boyang
Zhang, Rui
Li, Yajing
Zhang, Baoshou
Guo, Chao
Powiązania:
https://bibliotekanauki.pl/articles/1573694.pdf
Data publikacji:
2021
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
ship propulsion
flettner rotor
wind energy
rotating cylinder
numerical simulation
Opis:
Wind energy is a clean and renewable source of energy. This study seeks to explore the potential for utilising wind power for merchant ships. A new type of Flettner rotor (rotating cylinder) mounted on the superstructure of a ship is proposed and numerically simulated. The construction and installation of the rotating cylinder is designed and a numerical simulation of the ship-mounted cylinder is carried out, using the commercially available CFD code Ansys Fluent to obtain parameters such as lift and drag coefficient of the cylinder in different conditions. Specifically, it is found that the cylinder type superstructure can play a certain role in reducing the effect of friction by comparing traditional and cylindrical superstructures; the rotating cylinder can generate auxiliary thrust for the ship. After analysis, the wind speed around the cylinder and spin ratio will have a direct influence on its thrust effect; there is an inflection point in the lift coefficient with the increase of α; the thrust coefficient (8.63) reaches the maximum environmental wind speed at 10 m/s and spin ratio is 2.5. For the rotating cylinder, the greater the environmental wind, the greater the thrust contribution generated under the same spin ratio conditions. The maximum thrust can reach 750,000 N; the cylinder’s auxiliary propulsion contribution shows a better advantage in α = 2.0. The effective power generated by the cylinder reaches a maximum of 2,240 kW for environmental wind speed = 20 m/s and α = 1.0.
Źródło:
Polish Maritime Research; 2021, 1; 28-41
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł

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