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91.
The performance of multi-hop CSMA/CA networks has in most cases been evaluated via simulations, or analytically using a perfect collision channel model. Using such methods, one can neither have access to the capture nature of the terminals nor evaluate the performance of the network in a fading environment. In this paper a new analytical framework that takes into account these capture and fading effects is presented. The network investigated in this paper has an infinite number of nodes which is assumed to be spatially Poisson distributed. The approach is to develop analytical expressions for the transition probabilities between states of nodes in the network by approximating these states as a Markov chain. A fast algorithm to solve these equations is also given. Numerical results show that the model agrees with simulation results for both omni-directional networks and networks employing beamforming. 相似文献
92.
Xianfu Lei Rose Qingyang Hu Lisheng Fan Pingzhi Fan Trung Q. Duong 《Wireless Communications and Mobile Computing》2016,16(6):624-642
In this paper, we consider switch‐and‐stay combining (SSC) in two‐way relay systems with two amplify‐and‐forward relays, one of which is activated to assist the information exchange between the two sources. The system operates in either analog network coding (ANC) protocol where the communication is only achieved with the help of the active relay or time‐division broadcast (TDBC) protocol where the direct link between two sources can be utilized to exploit more diversity gain. In both cases, we study the outage probability and bit error rate (BER) for Rayleigh fading channels. In particular, we derive closed‐form lower bounds for the outage probability and the average BER, which remain tight for different fading conditions. We also present asymptotic analysis for both the outage probability and the average BER at high signal‐to‐noise ratio. It is shown that SSC can achieve the full diversity order in two‐way relay systems for both ANC and TDBC protocols with proper switching thresholds. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
93.
Vu Quoc Trung Trinh Hong Hanh Tran Hong Quang Ha Manh Hung Duong Khanh Linh Hoang Thi Tuyet Lan 《腐蚀工程科学与技术》2018,53(2):59-66
ABSTRACTPolypyrrole (PPy) was prepared on the mild steel substrate by electrochemical polymerisation in the solution containing pyrrole monomer and succinic acid. The mild steel surface could be passivated before and during electropolymerisation by molybdate. The morphology and structure of the PPy film were studied with SEM. The typical cauliflower structure of PPy was observed. Raman and IR spectroscopy showed that the obtained PPy was in an oxidised state. The thermal stability of PPy was investigated by the thermal gravimetric analysis, showing that PPy was stable at higher than 480°C. The electrochemical property of the PPy film was performed by open circuit potential, polarisation curves (I/E), and electrochemical impedance spectroscopy. The corrosion behaviour of mild steel (CT3) with PPy film in solution NaCl 3% was studied.This paper is part of a supplementary issue from the 17th Asia-Pacific Corrosion Control Conference (APCCC-17). 相似文献
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96.
Karsten König Peter Andersen Tuan Le Hans Georg Breunig 《Microscopy research and technique》2015,78(12):1154-1158
Multiphoton laser scanning microscopy commonly relies on bulky and expensive femtosecond lasers. We integrated a novel minimal‐footprint Ti:sapphire oscillator, pumped by a frequency‐doubled distributed Bragg reflector tapered diode laser, into a clinical multiphoton tomograph and evaluated its imaging capability using different biological samples, i.e. cell monolayers, corneal tissue, and human skin. With the novel laser, the realization of very compact Ti:sapphire‐based systems for high‐quality multiphoton imaging at a significantly size and weight compared to current systems will become possible. Microsc. Res. Tech. 78:1154–1158, 2015. © 2015 Wiley Periodicals, Inc. 相似文献
97.
Thang Ngoc Ngo Tuan Thanh Dang Alexander Villinger Peter Langer 《Advanced Synthesis \u0026amp; Catalysis》2016,358(8):1328-1336
We have developed a palladium(0)‐catalyzed tandem process which involves the cross‐coupling reaction of N‐tosylhydrazones with dibromide compounds followed by a sequence of intramolecular 5‐exo‐trig, 3‐exo‐trig cyclization, ring opening, and β‐hydride elimination to produce 6‐endo‐trig cyclized products. The strategy was successfully applied for the regioselective synthesis of substituted benzo[b]naphtho[2,1‐d]thiophenes, naphtho[1,2‐b]benzofurans, and benzo[a]carbazoles in moderate to excellent yields.
98.
Reena Amatya Shrestha Thuy Duong Pham Mika Sillanpää 《Journal of Applied Electrochemistry》2010,40(7):1407-1413
The polycyclic aromatic hydrocarbons (PAHs) with high molecular mass are renown for their high persistence in the soil, hydrophobic
and toxicity. Remediation of these pollutants is still an unsolved task and needs more researches to be performed. The coupling
of electrokinetics (EK) with ultrasonic energy (US) has advantages on desorbing and migrating PAHs from contaminated soil.
US and EK work together to destroy PAHs. The objective of this study was to treat PAHs contaminated soil by using EK and ultrasonication.
The contaminated oil contained about 100 mg kg−1 chrysene. Experiments with US, EK and combined EK and ultrasound were conducted in reactors and pans with and without iron
anodes. Results indicated that the removal was more effective with lower concentrations of chrysene. The average removal was
better in experiment with combined EK and ultrasound using iron anode. This might be due to increase in electroconductivity
by iron ions. 相似文献
99.
Khanh Tuan Le 《今日电子》2010,(3):44-45
今日相容于IEEE802.15.4且适用于ZigBee的无线射频收发器、微控制器及系统单芯片(SOC)半导体装置已相当普及。高度整合的多功能SOC解决方案是促成ZigBee无线网络得以广泛运用在众多应用中的重要因素,包括工业监控、家庭及建筑自动化、传感器网络,乃至于无线医疗解决方案。在以上解决方案中增添无线射频装置的定位功能使得这些网络的价值得以大幅提升。 相似文献
100.
Phuong Pham Thi Thuy Phuong Nguyen Nguyen Kumar P. Senthil Duy Nguyen Phuc Hoang Van Le Quyet Ngoc Le Thi Bao Jalil A. A. Rajendran Saravanan Cheng Chin Kui Nguyen Thanh-Huong Dinh Minh Tuan Nguyen Vo Dai-Viet N. 《Topics in Catalysis》2023,66(1-4):41-52
Topics in Catalysis - CO2 reforming of methanol for producing hydrogen was experimentally carried out in a fixed-bed reactor on 10%Ni/SiO2. The 10%Ni/SiO2 was completely reduced during H2... 相似文献