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151.
本文提出了一种抗非视线传播(Non-Line-of-Sight)干扰的TDOA定位算法。该算法采用退火与遗传算法相结合的方式,在满足给定条件的空间内搜索源点坐标值。数值仿真表明,该算法具备抗NLOS干扰的能力,与传统TDOA算法相比,该算法无需知道各基站的非视线传播干扰分布,是一种实用有效的定位算法。  相似文献   
152.
In this article we report the system structure and test results of an experimental optical burst switching network with three edge router's and one core node. Wavelength-selective switches developed for this system and their characteristics are depicted. The implementation and performance of our new scheme for the just-in-time protocol are described. We also report experimental results of FTP and VOD services on this system. Some parameters, including traffic rate, average burst data length, and assembly time, are studied.  相似文献   
153.
李治镇 《华中建筑》2005,23(B07):117-118
通过对汉口西商跑马场的调查,说明它移植武汉的经过和历程,以及它在建筑设计方面的一些特点。  相似文献   
154.
ShuJing Li  FeiPeng Wu  MiaoZhen Li 《Polymer》2005,46(25):11934-11939
Methylated-β-cyclodextrin (Me-β-CD) was used to complex the photoinitiator, 2,2-dimethoxy-2-phenyl acetophenone (DMPA), yielding a water-soluble host/guest complex. The comparative studies demonstrated that the Me-β-CD complexed DMPA exhibited a high photoreactivity identical to the uncomplexed DMPA, while the CD complex obviously influenced the products of primary photolysis of DMPA and the photopolymerization kinetics due to the steric effect of CD on the subsequent initiation reactions. The photopolymerization rate of acrylamide can be described by the equation: Rp=K[2a]0.62[M]1.37[I]0.5[Me-β-CD]0. The mechanism of polymerization was also discussed.  相似文献   
155.
李春曼 《中国橡胶》2008,24(21):21-21
本周(10月20~24日)亚洲天胶市场天胶价格小幅震荡,现货市场成交有限。期货沪胶在13000元震荡较为明显,市场商家仍多处于观望状态,对橡胶后市信心不足。本周CIF中国主港11月船期报价:泰国烟片胶RSS3外盘报价1640美元-1675美元/吨,泰国标准胶STR20外盘报价1550美元~1605美元/吨,印尼标准胶SIR20外盘报价1560美元~1580美元/吨,马来西亚标准胶SMR20外盘报价1670美元~1705美元/吨,越南标准胶SVR3L外盘报价1670美元-1705美元/吨,泰国乳胶外盘报价1340美元~1390美元/吨。本周国内天胶两大产区均未有成交,本周标准胶SCR5近期跟随期货市场价格波动,国内大部分销区市场主流报价在14700元~16000元/吨左右,下跌幅度高达1000元/吨左右。  相似文献   
156.
Oxide films were deposited on different substrates by laser molecular beam epitaxy. Reflection high-energy electron diffraction was performed to in situ investigate the change of growth mode and the lattice relaxation during the growth. An asymmetrical phenomenon was found in the two kinds of strain states, compressive stress and tensile stress of heterostructures with different lattice mismatch. In the case of BaTiO3/SrTiO3 (2.2%), 2D layer-by-layer growth mode without lattice relaxation can be maintained for a longer period for BTO films on STO with compressive stress, comparing to STO films on BTO with tensile stress. When MgO films were deposited on SrTiO3 with a large mismatch of 7.8%, compressive stress leads to rapid lattice relaxation with a very thin wet layer, and 3D strained island were observed. As a comparison, SrTiO3 films on MgO with tensile stress were configured. No RHEED patterns can be observed duo to a large tensile stress.  相似文献   
157.
Samples can be measured with different precisions and reliabilities in different experiments, or even within the same experiment. These varying levels of measurement noise may deteriorate the performance of a pattern recognition system, if not treated with care. Here we seek to investigate the benefit of incorporating prior knowledge about measurement noise into system construction. We propose a kernel density classifier which integrates such prior knowledge. Instead of using an identical kernel for each sample, we transform the prior knowledge into a distinct kernel for each sample. The integration procedure is straightforward and easy to interpret. In addition, we show how to estimate the diverse measurement noise levels in a real world dataset. Compared to the basic methods, the new kernel density classifier can give a significantly better classification performance. As expected, this improvement is more obvious for small sample size datasets and large number of features.  相似文献   
158.
The processes of phase formation in the Na2CO3-TiO2 and Na2CO3-TiO2-Nd2O3 systems are investigated in the temperature range 600–900°C. The high-temperature solid-phase reactions underlying the process of formation of complex oxide NaNdTiO4 are studied. It is established that the synthesis of the NaNdTiO4 compound occurs through the reaction of the intermediate product Na8Ti5O14 with neodymium oxide in the temperature range 720–780°C. The optimum method is proposed for synthesizing NaNdTiO4, which makes it possible to reduce the temperature of the synthesis, to avoid the formation of impurities, and to obtain the product in a finely dispersed state.  相似文献   
159.
160.
The Jian kiln, located in present-day Jianyang county of Fujian province, mainly produced black-glazed tea bowls. Jian tea bowl was used as a utensil for tea tasting and was greatly appreciated by emperor Huizong of the Northern Song dynasty. The black glaze of Jian bowl was sometimes marked with streaks or spots, usually called “hare's fur” or “oil spot”, which are the crystalline markings of iron oxide precipitated during firing in the dragon kiln. In this study, black-glazed Jian bowl sherds excavated from the late Northern Song strata of Luhuaping and Daluhoumen Jian kiln sites were adopted as test samples. Based on the physico-chemical foundation for the formation of glaze microstructure, the correlation among composition, microstructure, and visual appearance has been investigated by means of energy-dispersive X-ray fluorescence, X-ray diffraction, and field emission electron microscopy. For the first time, the study provides realizing proofs for two kinds of microstructural forming mechanics.  相似文献   
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