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Wyszukujesz frazę "Zhang, D." wg kryterium: Autor


Tytuł:
Survey of the Excited State Dissociation οf Gas-Phase Bromine Monochloride in the Visible-Near UV Wavelength Region
Autorzy:
Zhang, D.
Powiązania:
https://bibliotekanauki.pl/articles/1538637.pdf
Data publikacji:
2010-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
31.15.Qg
33.20.Kf
31.50.Gh
Opis:
The spectroscopic transitions and photoabsorption/dissociation processes of bromine monochloride (BrCl) via several low-lying covalently bound electronic states and repulsive states have been investigated by performing electronic structure calculations and wave packet simulations of nuclear motion. The absorption spectra for 52-electron singlet systems are obtained by employing time-dependent propagation methods or the real-time propagation of the time-dependent Schrödinger equations in the adiabatically exact approximation. Based on the elastic scattering calculations, the results of angular distributions of the products of photodissociation of BrCl molecules are examined on two aspects: (1) the nature of the state that is prepared by excitation from a bound level into a continuum, and (2) under avoided crossing cases, the influences of nonadiabatic coupling processes on the fragmentation process are evaluated by virtue of a semiclassical Landau-Zener model, which treats an avoided crossing between two states of a given nature and evaluates a nonadiabatic effect relevant to the molecule during photodissociation. The model qualitatively reproduces the key aspects of the full processes related to the transfer of dissociating flux between states of 0+ symmetry, indicating that the proposed coupling scheme is generally correct.
Źródło:
Acta Physica Polonica A; 2010, 117, 3; 457-465
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Heterogeneous photocatalytic removal and reaction kinetics of Rhodamine-B dye with Au loaded TiO2 nanohybrid catalysts
Autorzy:
Zhang, D.
Powiązania:
https://bibliotekanauki.pl/articles/779739.pdf
Data publikacji:
2012
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
rozpad kinetyczny
rodamina B
katalizator Au/TiO2
Au/TiO2 catalyst
rhodamine B
decompose kinetics
Opis:
Heterogeneous photocatalytic removal of Rhodamine-B (RhB) dye by metallic Au nanopatrticles deposited TiO2 photocatalyst was studied. For this study, a chemical reduction method by hydrazine hydrate for gold deposition was employed in order to synthesize Au/TiO2 nanocomposite system. For the characterization of the synthesized nanomaterials, X-ray diffraction (XRD), transmission electron microscopy (TEM), UV-vis diffuse reflectance spectroscopy (DRS), the Fourier transformation infrared spectroscopy (FTIR) and photoluminescence spectroscopy (PLS) techniques were performed. The obtained results show that the deposition of gold onto TiO2 surface could effectively inhibit the recombination of the photoinduced electron and holes, improving the absorption capability for the visible light source and leading to the increased surface OH group density. The degradation experiment reveals that the efficiency of color removal from RhB aqueous solution containing Au/TiO2 powders for the photocatalytic bleaching of RhB dye is more efficient than that of bare TiO2 sample upon UV-vis light activation. In addition, degradation kinetics of RhB dye in aqueous suspensions can be well simulated by the Langmuir-Hinshelwood model and obeys the pseudo-first order law, with a decolorization rate of 0.0252 min-1 to the photocatalytic removal of RhB dye.
Źródło:
Polish Journal of Chemical Technology; 2012, 14, 2; 42-48
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Charging station location optimization of electric ship based on backup coverage model
Autorzy:
Zhang, W.
Yan, X.
Zhang, D.
Powiązania:
https://bibliotekanauki.pl/articles/117632.pdf
Data publikacji:
2017
Wydawca:
Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
Tematy:
main engine
ship propulsion
charging station
electric ship
backup coverage model
electric ship energy
electric energy supply
ship charging station
Opis:
In terms of electric ship energy requirement in navigation, the ship charging station location is especially important. In this paper, a multi-period ship charging station location optimization model is pro-posed to make location decision in overall, from initial possible station sites chosen to the capacity determination for the final location sites. In the first phase, from the perspective of external environment, find out all possible ship charging station candidate sites through the feasible analyze. In the second phase, taking the ship charging demands into consideration, the final ship charging station sites can be selected among the candidate sites based on backup coverage model. In the last phase, regarding the cost of construction and service capability for different grade as the main factor in capacity determination, the optimal capacity of each final ship charging station are determined by means of optimization method. Finally, an example of Yanqi lake in China is used to verify the validity of the proposed methodology. The reasonable location of charging station could ensure the electric energy supply and avoid congestion caused by ship charging gathering. The model can be easily generalized to other problems regarding facility allocation based on user demand.
Źródło:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2017, 11, 2; 323-327
2083-6473
2083-6481
Pojawia się w:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
General concerns life-cycle design of economical ice-resistant structures in the Bohai Sea
Autorzy:
Zhang, D.
Yu, S.
Yue, Q.
Powiązania:
https://bibliotekanauki.pl/articles/258458.pdf
Data publikacji:
2017
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
ice zone
economical ice-resistant structure
life-cycle design
performance-based design
cost-effective code
Opis:
In China, the oil and natural gas resources of Bohai Bay are mainly marginal oil fields. It is necessary to build both iceresistant and economical offshore platforms. However, there are many risks during the life cycle of offshore platforms due to the imperfect preliminary design for the Bohai Sea economical ice-resistant structures. As a result, the whole life-cycle design should be considered, including plan, design, construction, management and maintenance design. Based on the demand of existing codes and research of the basic design, structural ice-resistant performance and the reasonable management and maintenance, the life-cycle design theory is discussed. It was concluded that the life-cycle cost-effective optimum design proposed will lead to a minimum risk.
Źródło:
Polish Maritime Research; 2017, S 2; 164-191
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigation and statistical analysis on the deterrence effect of police patrol
Autorzy:
Suo, Q.
Suo, R.
Zhang, D.
Powiązania:
https://bibliotekanauki.pl/articles/2140956.pdf
Data publikacji:
2018
Wydawca:
Fundacja Centrum Badań Socjologicznych
Tematy:
road crash
safety measure
drivers' behaviour and attitude
deterrence effects
Opis:
This study investigated the deterrence effect of the police patrol on the road safety in China and the research purpose was achieved by questionnaire survey and data regression. Firstly, a questionnaire survey was carried out to investigate the drivers’ illegal behaviours and attitudes to safety measures, such as police patrol, surveillance cameras and warning signs, and 137 drivers participated in the survey; the statistical results showed that 45.3%, 4.4% and 16.8% of the respondents had the experience of speeding, driving under influencing of alcohol and fatigued driving respectively; all of the participants believed that traffic police patrol would change their dangerous driving behaviours and police patrol is most effective among three road safety measures based on the investigations. Secondly, data about police patrol frequency and road crash rate on the road segment was collected from the local Transportation Administration Bureau and the regression analysis based on the data was conducted to investigate the direct effect of traffic police patrol on road safety improvement. The results indicated that increasing the frequency of police patrol has an obvious positive effect on improving the road safety and it is consistent with the results from self-reported questionnaire survey.
Źródło:
Journal of Sustainable Development of Transport and Logistics; 2018, 3, 3; 69-76
2520-2979
Pojawia się w:
Journal of Sustainable Development of Transport and Logistics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A prediction method for load distribution in threaded connections
Autorzy:
Zhang, D.
Gao, S.
Niu, S.
Liu, H.
Powiązania:
https://bibliotekanauki.pl/articles/949123.pdf
Data publikacji:
2018
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
load distribution
threaded connections
finite element analysis
Opis:
A new method has been developed for predicting the load distribution along the thread portion of a bolt and nut connection. The calculated results were validated by comparison with three-dimensional finite element analysis and Yamamoto’s method. It was shown that the load distribution predicted by the model in this paper was in good agreement with the results from finite element model, and the load ratio on the first thread by the prediction model and finite element model was slightly larger than the results from Yamamoto’s method. In addition, the results of calculation and finite element analysis indicated that the decreasing of the lead angle could improve the load distribution, the increasing of the length of thread engaged could significantly improve the load bearing capacity of the first thread, and the adopting of a material with low stiffness for the nut with respect to the bolt could improve the load distribution slightly.
Źródło:
Journal of Theoretical and Applied Mechanics; 2018, 56, 1; 157-168
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Phase Field Study of Microstructure Evolution in Eutectoid Phase Transformation – I Nucleation
Autorzy:
Zhang, D.
Yin, Y.
Zhou, J.
Tu, Z.
Powiązania:
https://bibliotekanauki.pl/articles/381800.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
eutectoid
nucleation models
microstructure
numerical simulation
phase field
eutektoid
ziarna
mikrostruktura
symulacja numeryczna
Opis:
Eutectoid growth, as the important reaction mechanism of the carbon steel heat treatment, is the basis to control the microstructure and performance. At present, most studies have focused on lamellar growth, and did not consider the nucleation process. Mainly due to the nucleation theory is inconclusive, a lot of research can support their own theory in a certain range. Based on the existing nucleation theory, this paper proposes a cooperative nucleation model to simulate the nucleation process of eutectoid growth. In order to ensure that the nucleation process is more suitable to the theoretical results, different correction methods were used to amend the model respectively. The results of numerical simulation show that when the model is unmodified, the lateral growth of single phase is faster than that of longitudinal growth, so the morphology is oval. Then, the effects of diffusion correction, mobility correction and ledges nucleation mechanism correction on the morphology of nucleation and the nucleation rate were studied respectively. It was found that the introduction of boundary diffusion and the nucleation mechanism of the ledges could lead to a more realistic pearlite.
Źródło:
Archives of Foundry Engineering; 2017, 17, 3; 155-162
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical investigation of root canal irrigation adopting innovative needles with dimple and protrusion
Autorzy:
Li, P.
Zhang, D.
Xie, Y.
Lan, J.
Powiązania:
https://bibliotekanauki.pl/articles/307257.pdf
Data publikacji:
2013
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
dimple
protrusion
innovative needles
numerical simulation
passive flow control methods
root canal irrigation
wychylenie zębów
symulacja komputerowa
kanał zębowy
Opis:
As important passive flow control methods, dimples and protrusions have been successfully implemented via geometric modifications to manipulate flow fields to get a desired flow parameters enhancement. In this research, two novel needles were proposed based on a prototype by means of the dimple and protrusion, and flow patterns within a root canal during final irrigation with these needles were numerically investigated. The calculation cases consistent with the clinically realistic irrigant flow rates, which are 0.02, 0.16 and 0.26 mL s–1 are marked as case A, B and C, respectively. The characteristic parameters to estimate irrigation efficiency, such as shearing effect, mean apical pressure, irrigation replacement and fluid agitation, were compared and the optimal geometry in every calculation case was obtained. As shown from the results, flow rates and needle geometries were the causes of irrigation parameters variations. The sum of shear stress, irrigation replacement and fluid agitation were equal in the low flow rate case A, however, the needle with a protrusion on its tip had advantages in the three irrigation characteristic parameters above in calculation case B, and the needle with a dimple on its tip had advantages in calculation case C. Furthermore, the needles proposed did not give rise to the risk of irrigant extrusion. These needles can be better choices at larger flow rates. Therefore, needle geometry optimizations utilizing passive flow control methods are worthy to be investigated in the root canal irrigation enhancement.
Źródło:
Acta of Bioengineering and Biomechanics; 2013, 15, 1; 43-50
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sea ice management for oil and gas platforms in the Bohai Sea
Autorzy:
Zhang, D.
Yu, S.
Wang, Y.
Yue, Q.
Powiązania:
https://bibliotekanauki.pl/articles/258746.pdf
Data publikacji:
2017
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
Bohai
sea ice management
ocean platform
ice-induced vibration
ice risk prediction
Opis:
Bohai is a typical marginal oil field in an ice region, where most of the oil and gas platforms are economical. Sea ice is the main factor that affects the safety of oil and gas platforms in Bohai. Due to the complexity of the ice load and ice-induced vibrations, there are large security risks when developing Bohai oil and gas in the winter. It is difficult to ensure the safe production of oil and gas in winter using existing sea ice disaster warning technologies. Based on winter oil and gas production in the Bohai Sea’s Liaodong Bay, a set of suitable sea ice management systems is proposed in this paper. These systems integrate sea ice monitoring, risk assessment and risk prediction technologies. Based on the risk warning system, an ice management model of a Bohai ice platform has been put into practice, which ensures the safe production of the platform in winter.
Źródło:
Polish Maritime Research; 2017, S 2; 195-204
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ship Trajectory Control Optimization in Anti-collision Maneuvering
Autorzy:
Zhang, J. F.
Yang, X. D.
Zhang, D.
Haugen, S.
Powiązania:
https://bibliotekanauki.pl/articles/116373.pdf
Data publikacji:
2013
Wydawca:
Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
Tematy:
anticollision
ship trajectory
genetic algorithm
route optimization
Opis:
A lot of attention is being paid to ship’s intelligent anti‐collision by researchers. Several solutions have been introduced to find an optimum trajectory for ship, such as Game Theory, Genetic or Evolutionary Algorithms and so on. However, ship’s maneuverability should be taken into consideration before their real applications. Ship’s trajectory control in anti‐collision maneuvering is studied in this paper. At first, a simple linear ship maneuverability model is introduced to simulate its movement under different speed and rudder angle. After that, ship’s trajectory control is studied by considering the duration of rudder, operation distance to turning points, and maximum angular velocity. The details for algorithm design are also introduced. By giving some restrictions according to the requirements from COLREGs, the intervals for rudder angle in different circumstances can be determined based on the curves. The results can give very meaningful guidance for seafarers when making decisions.
Źródło:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2013, 7, 1; 89-93
2083-6473
2083-6481
Pojawia się w:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Focus shaping of the radially polarized Bessel–Gauss beam with a sine-azimuthal variation wavefront
Autorzy:
Gao, X
Zhang, D.
Mei, T.
Fu, R.
Zhuang, S.
Powiązania:
https://bibliotekanauki.pl/articles/174283.pdf
Data publikacji:
2013
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
Bessel-Gauss beam
wavefront modulation
vector diffraction theory
Opis:
Focusing properties of the radially polarized Bessel–Gauss beam with a sine-azimuthal variation wavefront was investigated by the vector diffraction theory. The wavefront distribution is the sine function of the azimuthal angle with one phase parameter that indicates the phase change frequency. Results show that the focal pattern can be altered by the phase parameter, and many novel focal patterns may occur, such as multiple dark-foci focal pattern, crescent shape, and wheel shape. For case of a higher phase beam, the whole focal pattern turns on a symmetric wheel shape with multiple reduplicate intensity elements. When the phase parameter is an odd number, the number of reduplicate elements equals the phase parameter, while when the phase parameter is an even number, the number of reduplicate elements is two times the phase parameter. In addition, the effect of the phase parameter on the focal pattern is more considerable than that of the beam parameter under low numerical aperture. Under higher numerical aperture, the effect of the beam parameter on the focal pattern gets stronger.
Źródło:
Optica Applicata; 2013, 43, 3; 567-582
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Focusing of linearly polarized helico-conical Lorentz beam with sine-azimuthal variation wavefront
Autorzy:
Bao, Y.
Lan, J.
Miao, Y.
Zhang, D.
Gao, X.
Powiązania:
https://bibliotekanauki.pl/articles/174305.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
Lorentz beam
focusing properties
optical vortex
Opis:
In this article a theoretical research is described into focusing of a linearly polarized helico-conical Lorentz beam with a sine-azimuthal variation wavefront. The simulation results show the vortex charge on the axis, which has an obvious modulation effect on the focal modes of the Lorenz beam under certain beam parameters and phase parameters. Both the phase parameter and the vortex charge are zero, the focal spot appears round. The focal spot is symmetric about y axis when the charge is 0 and the phase parameter is adjusted. And the focal evolution patterns vary remarkably under different beam parameters and the phase parameters. In the process of focus evolution, there appears some novel focal patterns, such as a circle, a “T”, a butterfly, a small running humanoid, a whale tail, a flower of four leaves, a serpentine, a goldfish, a Chinese knot and an octopus, which indicates that the focus mode of the optical vortex Lorentz beam can be altered by changing the phase parameters and vortex charge.
Źródło:
Optica Applicata; 2018, 48, 3; 373-387
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Emergency management of maritime accidents in the yangtze river: problems, practice and prospects
Autorzy:
Yan, X.P.
Wu, B.
Zhang, D.
Zhang, J. F.
Powiązania:
https://bibliotekanauki.pl/articles/117335.pdf
Data publikacji:
2017
Wydawca:
Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
Tematy:
inland navigation
emergency management
Yangtze River
maritime accidents
artificial societies
Computational Experiments and Parallel Execution (ACP)
eastern star
inland shipping
oil spill
Opis:
Maritime accidents have received considerable attentions due to the enormous property damage, casualties and serious environmental pollution. This paper first makes statistical analysis of the different types of maritime accidents in the period of 2012 to 2014 in the Yangtze River. Second, the problems of emergency management of maritime accidents are also proposed from the analysis of the major accident “Eastern Star”.. Afterwards, four practice cases, including decision support for maritime accidents, emergency resource allocation, emergency simulation system and effectiveness of emergency management, are introduced to present the insights gained from these practices. Last, in order to address these problems, this paper proposes that an artificial societies, Computational experiments, and Parallel execution (ACP) approach should be introduced to establish an improved management system for maritime accidents in the future, and an ACP based maritime accident emergency management framework is proposed.
Źródło:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2017, 11, 1; 111-118
2083-6473
2083-6481
Pojawia się w:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Characteristics of Magnetic Core in Magnetic Pulse Compression System
Autorzy:
Zhang, D.
Yan, P.
Sun, Y.
Wang, J.
Zhou, Y.
Pan, R.
Powiązania:
https://bibliotekanauki.pl/articles/1807880.pdf
Data publikacji:
2009-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
07.05.Tp
42.65.Re
75.60.Ej
Opis:
In order to obtain the characteristics of magnetic core under ≈0.5-5 μs saturation time, a one-stage magnetic pulse compression circuit without external demagnetization circuits which are commonly used in magnetic compressors is designed. The current through the core is calculated by voltage across the resistive load, and the loop voltage is picked up with a single wire loop and integrated by software. B-H curves are derived from the measured voltage and current wave forms. B-H curves show that the core loss is in inverse proportion to the time to saturation, whereas the percentile core loss decreases as the charging energy increases. While the eddy current loss and dissipated energy are in direct proportion to dB/dt. The low inductance of magnetic switch indicates that the core is saturated and behaves as an air core. By applying custom characteristics to each stage in Pspice simulation, more practical energy transfer in magnetic pulse compression and the effects of leakage current are presented.
Źródło:
Acta Physica Polonica A; 2009, 115, 6; 1001-1003
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synchronization Study and Introductory Experiment οf Laser-Triggered Surface Flashover in Voltage Pulse
Autorzy:
Pan, R.
Wang, J.
Sun, Y.
Sun, G.
Yan, P.
Zhang, D.
Powiązania:
https://bibliotekanauki.pl/articles/1807974.pdf
Data publikacji:
2009-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
52.80.-s
51.50.+v
Opis:
With the aim of studying the characteristics of laser-triggered surface flashover in voltage pulse, synchronization problem of laser pulse and voltage pulse should be solved. A single/double harmonic, with wavelength λ of 1064/532 nm, Q-switched Nd:YAG laser is used to trigger the surface flashover. The synchronization problem is solved using a self-made digital delay/pulse generator. The delay time and jitter of Marx's trigger input and output, Marx's trigger output and Marx's output, laser input and output are respectively measured. Based on the result of the delay time and the timing sequence of the laser triggering system, the synchronization of laser pulse and voltage pulse is obtained through adjusting the channel delay time of digital delay/pulse generator. In addition, introductory experiment of laser-triggered surface flashover is carried out using the flat electrodes and columned insulators.
Źródło:
Acta Physica Polonica A; 2009, 115, 6; 1167-1169
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł

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