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101.
102.
随着网络带宽的进一步提高,视频点播的瓶颈基本卡在视频服务器端。文章提供的服务器端的流式拷贝,能进一步提高整个系统的服务能力。文章对流式拷贝的过程进行描述,对其中的数学模型进行分析,并与没有流式拷贝的系统进行比较分析。 相似文献
103.
Buller G.S. Warburton R.E. Pellegrini S. Ng J.S. David J.P.R. Tan L.J. Krysa A.B. Cova S. 《Optoelectronics, IET》2007,1(6):249-254
The application of quantum key distribution (QKD) has raised particular demands for single-photon detectors. One of the most promising candidates at the low-loss optical fibre communications windows is the planar geometry InGaAs/InP single-photon avalanche diode. These detectors have been modelled, fabricated and characterised at 1.55 mum wavelength. Their performance in terms of single-photon detection efficiency, dark count rate, timing jitter and afterpulsing behaviour are reported and compared with the best commercially available, linear multiplication avalanche photodiodes operated in Geiger-mode. Their use in the application of QKD is discussed. 相似文献
104.
The effects of boiling Aqua Regia (AQ), N2/Cl2 plasma followed by AQ and O2 plasma followed by AQ surface treatments prior to Ni/Au (20 nm/20 nm) metallization to p-GaN:Mg (∼ 3 × 1017 cm− 3) have been investigated. N2/Cl2 plasma was employed in a bid to lower the Ga/N and O/Ga ratios of the GaN surface to improve the contact properties to p-GaN, while O2 plasma was employed as an alternative to incorporate O into the Ni/Au system. Results show that a low Ga/N ratio does not necessarily correspond to a better contact. The positive effect of O2 over N2 anneal is observed only for the AQ-treated sample, although the mechanisms responsible for its positive effect: NiO formation and Ni/Au layer-reversal were observed for all O2-annealed contacts. We conclude that the effect of O2 anneal on the Ni/Au contact is dependant on the p-GaN surface prior to metallization. 相似文献
105.
The influence of Zr addition on magnetic properties and temperature coefficient for nanocomposite Nd10Fe78.5-xCO5ZrxB6.5 (x=0~4) bonded magnets was investigated. It was found that the room-temperature magnetic properties were remarkably improved with Zr addition due to the grain refinement and increasing volume fraction of the hard magnetic phase. The optimal magnetic properties of Jr=0.689T, iHc=769.4kA·m-1 and (BH)max=84kJ·m-3 were obtained for 2.5% Zr addition. The temperature coefficient of remanence (α) increases slightly and the temperature coefficient of coercivity (β) decreases obviously with increasing Zr content for nanocomposite Nd10Fe78.5-xCo5ZrxB6.5 (x=0~4) bonded magnets. 相似文献
106.
107.
Duringthelastdecade ,thedesignandsynthesisoftripodalligandsandtheirmetalcomplexeshaveattractedconsiderableattentionduetotheirpotentialusesaslumi nescentprobesinmedicineandbiochemistry[1~ 7] ,ascatalysts[8] andelectrochemicalmaterials[9] .However ,thecomplexesofrareearthmetalwithtripodalligandshavefewreported[10 ] .Asanextensionofourstudiesoncomplexesofmetalwithtripodalligands ,anewtripodalligand (tris { 2 [N (pyridine methanoyl)amino]ethyl}amine ,L)anditscomplexeswithrareearthnitratesweresyn… 相似文献
108.
We propose a method for non-uniform reconstruction of 3D scalar data. Typically, radial basis functions, trigonometric polynomials or shift-invariant functions are used in the functional approximation of 3D data. We adopt a variational approach for the reconstruction and rendering of 3D data. The principle idea is based on data fitting via thin-plate splines. An approximation by B-splines offers more compact support for fast reconstruction. We adopt this method for large datasets by introducing a block-based reconstruction approach. This makes the method practical for large datasets. Our reconstruction will be smooth across blocks. We give reconstruction measurements as error estimations based on different parameter settings and also an insight on the computational effort. We show that the block size used in reconstruction has a negligible effect on the reconstruction error. Finally we show rendering results to emphasize the quality of this 3D reconstruction technique. 相似文献
109.
Decentralized control design for large-scale systems with strong interconnections using neural networks 总被引:2,自引:0,他引:2
We propose a decentralized neural network (NN) controller for a class of large-scale nonlinear systems with the strong interconnections. The NNs are used to approximate the unknown subsystems and interconnections. Due to the functional approximation capabilities of NNs, the additional precautions are not required to be made for avoiding the possible control singularity problems. Semiglobal asymptotic stability results are obtained and the tracking error converges to zero. Furthermore, the issue of transient performance of the subsystems is also addressed under an analytical framework. 相似文献
110.