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半参数测量模型在GPS高程拟合中的应用

武汉工业学院学报 2004年第2期23卷 99-101,108页

作者：潘雄武汉工业学院数理科学系湖北武汉430023

利用罚最小二乘原理构造加权惩罚平方和,将半参数回归模型与最小二乘配置结合起来,来处理GPS高程问题,导出了配置型模型中正规化矩阵正定时参数平差的计算方法,用直接法得到了参数和信号的估计量,给出了相应的公式。其次,通过选取合适... 详细信息

利用罚最小二乘原理构造加权惩罚平方和,将半参数回归模型与最小二乘配置结合起来,来处理GPS高程问题,导出了配置型模型中正规化矩阵正定时参数平差的计算方法,用直接法得到了参数和信号的估计量,给出了相应的公式。其次,通过选取合适的平滑因子,能使残差的分布更接近其真实分布,并用一个实例说明了此方法的有效性。

关键词：半参数测量模型 GPS 高程拟合罚最小二乘原理平滑参数正规化矩阵

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用截面映象非线性延时反馈控制混沌

物理学报 1996年第7期45卷 1100-1106页

作者：杨世平田钢徐树山胡岗河北师范学院物理系石家庄050091 北京师范大学物理系北京100875

提出了利用相空间oincare截面上的非线性延时反馈稳定微分动力系统混沌吸引子中不稳定周期轨道的新方法.以Henon映象和带注入信号的双光子激光系统为例，给出了理论分析和数值模拟结果．这种方法的主要特点是不需要获取混沌系统中不稳... 详细信息

提出了利用相空间oincare截面上的非线性延时反馈稳定微分动力系统混沌吸引子中不稳定周期轨道的新方法.以Henon映象和带注入信号的双光子激光系统为例，给出了理论分析和数值模拟结果．这种方法的主要特点是不需要获取混沌系统中不稳定周期轨道的任何信息，并且可以在混沌态的任意时刻施加控制作用．

关键词：混沌控制非线性系统延时反馈控制

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电子多声子作用对散射时间的效应

物理学报 1989年第1期38卷 154-158页

作者：刘福绥范希庆刘砚章王淮生阮英超北京大学物理系郑州大学物理系黑龙江大学物理系

本文给出电子多声子作用对电子寿命影响的一般讨论方法,同时给出温度T德拜温度T_D的表达式,指出YBaCuO体系中电子多声子作用对高温超导性可能是重要的。

关键词：电子多声子散射

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CuCl微晶光透射谱实验研究

中国激光 1995年第2期22卷 120-122页

作者：王德煌王威礼马季铭程虎民毛节泰北京大学物理系北京大学化学系北京大学地球物理系

报道了ＣｕＣｌ微晶的近紫外和可见光透射谱的实验研究结果。同时给出了Ｈｅ－Ｎｅ激光辐照下的透射谱，发现３８９．０８ｕｍ波长处出现一个宽度为０．６４ｕｍ的透射尖峰。

关键词：微晶光透射激光辐照氯化铜

The Preparation and Properties of New Silver-Metal Oxide Graded Composite Electrical Contact Materials

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The Preparation and Properties of New Silver-Metal Oxide Gra...

Preliminary study on PAH degradation by bacteria from contami-nated sediments in Xiamen Western Sea, Fujian, china

The 3～〔rd〕International Conference on High-Performance Ceramics(CICC-3)（2.

作者： Y. Wang F. Zhang L. Z. Qi L. Wang and L. C. Cheng department of physics Huazhong University of Science & Technology Wuhan 430074 {2.

＜正＞ Electrical contact material is a very important material for the electric power industry. An electrical contact material should display good structural characteristics （suitable hardness, high thermal conductivity and stabilization） as well as a good functional characteristic （low electrical resistivity）. It is difficult to fabricate such a contact material with all these good performing parameters by common techniques because these physical parameters influence each other. In this paper, we report a novel investigation to design and prepare silver-metal oxide composite materials according to functionally layered and graded material （FLGM） concept and meeting requirement as electrical contact material. The silver-based composite samples characterized by layered component were prepared with conventional solid-phase sintering technique. One kind of sample consists of tin dioxide and silver material, in which SnO2.exhibits a graded distribution. Another consists of two metal oxides, cadmium and zinc oxides, and silver material, in which each layer has different metal oxide. Hardness, thermal conductivity and electrical conductivity, were measured and related problems are discussed. Especially, welding resistance as an important parameter for practical application was tested. SEM analyses before and after electrical erosion were also performed. We conclude that the functionally graded material （FGM） concept as a novel designing and fabricating method has potential for electrical contact composite material.

关键词： Metal oxide Silver Electrical contact Functionally graded material

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Chinese Journal of Oceanology and Limnology 2004年第4期22卷 431-435页

作者：哈里德郑天凌洪华生俞志明袁建军department of Biology Quanzhou Normal College Quanzhou 362.00 china 胡忠 School of Life Sciences Xiamen University Key Lab. of Marine Environmental Science China Ministry of Education Xiamen 361005 China Key Lab. of Marine Ecology & Environmental Science Chinese Academy of Sciences Qingdao 266071 China

In order to estimate the biodegradation of three polycyclic aromatic hydrocarbons (PAHs) compounds, bacterial strains were isolated from marine sediments in three heavily contaminated sites (Yuandang Lake, Dongdu Port and Aquacultural zones in Maluan Bay) in Xiamen Western Sea. The results show three bacterial strains, which used pyrene as the sole carbon source, were identified as strains of Aureobacterium sp., Arthrobacter sp., Rhodococcus sp. The PAH-degrading bacteria isolated had a strong ability to degrade phenan-hrene, fluoranthene and pyrene at different degradation rates. The highest degradation rate was observed when three PAH compounds were mixed with an individual strain in the medium. The three PAHs were degraded after one week with a degradation rate of 89.94 % for phenanthrene and 93.4 % for both of fluoranthene and pyrene. In addition, after 2. days of incubation, the degradation rate was 99.98 % for phenanthrene and 99.97 % for both of fluoranthene and pyrene. Optical density was measured to estimate bacterial growth during the degradation of PAHs. Highest levels of bacterial growth were observed with a three PAH mixture in the culture, suggesting that the concentration of PAHs influenced bacterial growth and the highest levels of degradation for most series were detected after one week of incubation.

关键词： PAHs biodegradation bacteria Xiamen Western Sea

GaAs-Ga1-xAIxAs双异质结激光器欧姆接触的研究

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北京大学学报(自然科学版) 1975年第4期 128-135页

作者： Laser Group of physics department, Peking University 北京大学物理系激光一组

我们用正交表研究GaAs的欧姆接触工艺,实验结果表明,p—GaAs甩Au—Cr金、n—GaAs用Ag—Sn合金的欧姆接触工艺,比接触电阻率Rc<10（欧姆）(厘米)应用于GaAs—GaAlAs双异质结激光器,得到良好的效果。

关键词：欧姆接触双异质结激光器 x)AI_xAs GaAs-Ga AI

Defects in Electron Irradiation Te-doped GaSb Studied by Positron Lifetime Spectroscopy

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Defects in Electron Irradiation Te-doped GaSb Studied by Pos...

ON THE BOUND STATE EQUATION OF MESONS AND ITS SOLUTIONS

The 9th International Workshop on Positron and Positronium Chemistry

作者： H.Li J.Y.Ke J.B.Pang B.Wang Z.Wang~* department of physics Wuhan University Wuhan 430072.P.R.{2.

＜正＞Gallium antimonide （GaSb） is a Ⅲ-Ⅴ semiconductor with a narrow band gap of 0.7 eV at 300 K and 0.81 eV at 2.*** has small effective electron mass and high electron mobility. Due to its potential applications in low loss optical fibers and high efficiency solar cells researches on GaSb have been *** defects play an important role in the electrical and optical properties of GaSb,a much better understanding of existence and stability of defect structures is required.

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Science in china,Ser.A 1978年第1期 44-61页

作者：冼鼎昌吴坚武计数高仑 Institute of High Energy physics Academia Sinica department of Mathematics Szechuan University department of physics

A possible bound state equation of mesons is proposed, which is an integral equation of the Bethe-Salpeter type, and is relativistically covariant. The integral kernel in the equation is not the one as given by the ladder approximation, but is introduced phenomcnologically in accordance with the super strong interaction of a potential well type. Under the approximation of the straton model, the bound state equation of mesons is expanded in terms of four dimensional spherical harmonics and numerical solutions are obtained on a computer. It is found that there exist two kinds of solutions: the ground state solution and the excited state solution. The wave function of the latter solution oscillates in the configuration space, corresponding to an average potential well with a large area. The calculation results show that only potential well with a very flat bottom could lead to a bound state wave function of mesons with large average radius as evidenced by experimental results.

关键词： well ON THE BOUND STATE EQUATION OF MESONS AND ITS SOLUTIONS