检索结果-南通市图书馆

Coordinated Resource Allocation for Satellite-Terrestrial Coexistence Based on Radio Maps

在线全文

学校读者我要写书评

暂无评论

China Communications 2018年第3期15卷 149-156页

作者： yanmin wang Zhou Lu China Academy of Electronics and Information Technology Beijing 100041 China

Coexistence of satellite and terrestrial wireless communication systems in the same frequency band is quite promising for addressing the challenge of spectrum scarcity. To cope with the inevitable inter-system interference, radio resource allocation at both sides should be carefully re-optimized. In this paper, we focus on a scenario where a satellite communication system and a terrestrial distributed antenna system(DAS) coexist via spectrum sharing. We particularly utilize the radio map(RM) to reduce the system overhead for channel acquisition. Based on the large-scale channel state information at the transmitter(CSIT), which is derived from the RM, we propose an optimized power allocation scheme to improve the achievable sum rate of the terrestrial system. For the satellite side, an opportunistic user scheduling scheme is presented, to reduce the harmful leakage interference to the terrestrial mobile users. Simulation results demonstrate that the proposed RM-based coordination scheme can significantly promote the performance of satellite terrestrial coexistence, although the small-scale channel fading has been ignored in the formulated optimization.

关键词： satellite terrestrial coexistence distributed antenna system (DAS) radio map(RM) resource allocation

Prediction of aggregation behavior of submicron-sized particles of praseodymium-doped zirconium silicate in aqueous suspension by population balance model

在线全文

学校读者我要写书评

暂无评论

Particuology 2016年第2期14卷 83-92页

作者： Libin Liang yanmin wang Zhidong Pana, School of Materials Science and Engineering South China University of Technology Guangzhou 510640 China Guangdong KITO Ceramics Co. Ltd. Foshan 528031 China

The aggregation behavior of submicron-sized particles of praseodymium-doped zirconium silicate, a ceramic pigment, in aqueous suspension was predicted by a modified population balance model, In the model, the collision frequencies were selected to describe evolution of the particle size distribution of the suspension. The collision efficiency was estimated as a function of interaction potential between particles based on Derjaguin-Landau-Verwey-Overbeek theory. The population balance model was modified to predict the stable state of the aggregation by introducing the volume mean size of aggregate to stability ratio. In addition, aggregation of the particles in aqueous suspension in the presence of sodium dodecyl benzene sulfonate or potassium chloride was experimentally investigated. The predicted data （i.e., the final aggregate size, aggregation rate, and particle size distribution） were similar to the experimentalresults.

关键词： Population balance model Aggregation Surface forces Colloidal suspensions Praseodymium-doped zirconium silicate

Synthesis and characterization of (Ni,Sb)-co-doped rutile ceramic pigment via mechanical activation-assisted solid-state reaction

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Particuology 2018年第6期16卷 20-29页

作者： Shi Zhang Zhidong Pan yanmin wang School of Materials Science and Engineering South China University of TechnologyGuangzhou 510640China

(Ni,Sb)-co-doped rutile yellow ceramic pigments were synthesized via a mechanical activation-assisted solid-state reaction in a stirred bead *** effects of mechanical grinding of the raw materials on the synthesis of (Ni,Sb)-co-doped rutile pigment were *** results show that mechanical activation effectively decreased the crystallinity of the mixed precursors,thus enhancing their reactivity and the migration rate of *** effects lowered the temperature required for formation of the rutile *** with results from a mixture of separately ground precursors,the mixture of raw materials ground together was more effective for accelerating nickel/antimony ions doping into the TiO2structure and improved the color performance of the *** pigment from the mixed raw materials ground for 2.0h and heat-treated at 1100℃ could be used as an environmentally-friendly ceramic yellow pigment owing to its low-toxicity,bright yellow hue,good chemical/thermal durability, and high cost-effectiveness.

关键词： Mechanical activation Solid-state synthesis (Ni,Sb)-co-doped rutile Ceramic pigment

Inversion of particle size distribution from light-scattering data using a modified regularization algorithm

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Particuology 2010年第4期8卷 365-371页

作者： yanmin wang Guobiao Liang Zhidong Pan College of Materials Science Engineering South China University of Technology Guangzhou 510640 China Key Laboratory of Specially Functional Materials and Advanced Manufacturing Technology Ministry of Education South China University of Technology Guangzhou 510640 China

A modified regularization algorithm with a more proper operator was proposed for the inversion of particle size distribution （PSD） from light-scattering data in a laser particle sizer based on the Mie scattering principle. The Generalized Cross-Validation （GCV） method and the L-curve method were used for deter- mining the regularization parameter. The Successive Over-Relaxation （SOR） iterative method was used to increase the exactness and stability of the converged result. The simulated results based on the modified algorithm are in a good agreement with the experimental data measured for nine standard particulate samples, their mixtures as well as three natural particulate materials with irregular shapes, indicating that this modified regularization method is not only feasible but also effective for the simulation of PSD from corresponding light-scattering data.

关键词： Particle size measurement Mie scattering Laser particle size analyzerInverse algorithm

Weakly magnetic field-assisted synthesis of magnetite nano-particles in oxidative co-precipitation

在线全文

学校读者我要写书评

暂无评论

Particuology 2009年第5期7卷 363-367页

作者： Dawei Hu yanmin wang Qi Song College of Materials Science and Engineering South China University of Technology 510640 Guangzhou China Key Laboratory of Special Functional Materials under Ministry of Education 510640 Guangzhou China

This paper presents experimental results on weakly magnetic field-assisted synthesis of magnetite （Fe3O4） nano-particles in an oxidative co-precipitation method, in comparison to the case without magnetic induction. The XRD results show that a weakly magnetic induction below 220 Gs could accelerate the phase transformation from goethite （α-FeOOH） to magnetite （Fe3O4）, and affect the crystal structure, the particle size/morphology and magnetic response of the magnetite nano-particles synthesized. In addition, a higher concentration of the FeCl2 solution in the synthesis reaction led to finer particles, both with and without magnetic induction.

关键词： Magnetic field Oxidative co-precipitation Nano-particle Magnetite Morphology

Effect of alkalis on deacetylation of konjac glucomannan in mechano-chemical treatment

在线全文

学校读者我要写书评

暂无评论

Particuology 2011年第3期9卷 265-269页

作者： Zhidong Pan Junjie Meng yanmin wang School of Materials Science and Engineering South China University of Technology Guangzhou 510640 China Key Laboratory of Specially Functional Materials and Advanced Manufacturing Technology Ministry of Education South China University of Technology. Guangzhou 510640 China

This paper presents experimental results on the effect of alkalis such as NaOH, KOH and Ca（OH）2 on deacetylation of a konjac glucomannan （KGM） powder under mechano-chemical （MC） treatment, The results show that the alkalinity of modifiers is a dominant factor for deacetylation of KGM, In addition, characteristics, such as swelling property, viscous stability and thermal behavior of the deacetylated KGM are analyzed

关键词： Deacetylation Alkali Mechano-chemistry Konjac glucomannan

Electrical and thermal performances of photovoltaic/thermal systems with magnetic nanofluids:A review

在线全文

学校读者我要写书评

暂无评论

Particuology 2021年第1期19卷 181-200页

作者： Innocent Nkurikiyimfura yanmin wang Bonfils Safari Emmanuel Nshingabigwi Physics Department School of ScienceCollege of Science and TechnologyUniversity of RwandaKigaliRwanda African Center of Excellence in Energy for Sustainable Development(ACE-ESD) College of Science and TechnologyUniversity of RwandaKigaliRwanda School of Materials Science and Engineering South China University of TechnologyGuangzhouChina

Enhancing solar photovoltaic and thermal conversion performances may help develop more environmentally friendly hybrid photovoltaic/thermal(PV/T)systems that can be used in applications ranging from household to industrial *** to their enhanced thermal and optical properties,nanofluids have proven to be good candidates for designing PV/T systems with superior *** smart nanofluids,magnetic nanofluids(MNFs)can further enhance the performances of PV/T systems under external magnetic *** paper reviews recent developments in enhancing the electrical and thermal performances of PV/T systems using magnetic *** parameters affecting the performances are highlighted,and some areas for further investigations are *** reviewed literature shows that PV/T systems with MNFs are ***,their performances need further investigation before they can be used in applications.

关键词： Magnetic nanofluids Photovoltaic/thermal systems Heat transfer enhancement Magnetic field Electrical and thermal performances Solar energy

Deviation matrix and asymptotic variance for GI/M/1-type Markov chains

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Mathematics in China 2014年第4期9卷 863-880页

作者： Yuanyuan LIU Pengfei wang yanmin XIE School of Mathematics New Campus Central South University Changsha 410083 China

We investigate deviation matrix for discrete-time GI/M/1-type Markov chains in terms of the matrix-analytic method, and revisit the link between deviation matrix and the asymptotic variance. Parallel results are obtained for continuous-time GI/M/1-type Markov chains based on the technique of uniformization. We conclude with A. B. Clarke＇s tandem queue as an illustrative example, and compute the asymptotic variance for the queue length for this model.

关键词： GI/M/1-type Markov chains deviation matrix asymptoticvariance matrix-analytic method

Spectra of ZnO nanoparticles under low photon energy excitation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Particuology 2009年第6期7卷 496-500页

作者： Xiaofang wang Pingbo Xie Fuli Zhao Hezhou wang yanmin wang College of Materials Science and Engineering South China University of Technology Cuangzhou Guangdong 510641 China State Key Laboratory of Optoelectronic Materials and Technologies Sun Yat-Sen University Guangzhou Guangdong 510275 China

Time-integrated photoluminescence （PL） spectra between 1.2 and 2.25 eV of ZnO nanoparticles were observed at ambient temperatures when they were excited by a picosecond （ps） laser pulse at a low photon energy of 2.33 eV/532 rim, to show clear red shift when the excitation intensiW increased. Gaussian analysis shows that the red shift is due to increase of the relative magnitudes of the Gaussian combination in the low energy region. Temporal evolution of the dominant emissions exhibited a similar double-exponential decay process, in which the respective two distinct decay durations of 189 ps at the corresponding amplitude of 82% and 2081 ps at 18% were identified. Speculation based on the surfacestate emission due to the large surface-to-volume ratio of nanoscale materials is used to explain the phenomena.

关键词： ZnO nanoparticles Time resolved Surface emission