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Multi-target state-estimation technique for the particle probability hypothesis density filter

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Science China(Information Sciences) 2012年第10期55卷 2318-2328页

作者： LIN LiangKui 1,2,XU Hui 1,SHENG WeiDong 1 & AN Wei 1 1 School of Electronic Science and Engineering,national University of Defense Technology,Changsha 410073,China 2 95507 Unit,Chinese People's Liberation Army,Guiyang 550031,China School of Electronic Science and Engineering National University of Defense Technology Changsha China 95507 Unit Chinese People’s Liberation Army Guiyang China

A simple yet effective state-estimation algorithm is presented and demonstrated to have advantages over previous standard clustering techniques used for the particle probability hypothesis density *** idea behind the proposed algorithm is that it uses the latest available information(i.e.,the measurements) to direct particle *** particle likelihood and target number estimation,computed during probability hypothesis density recursion,are both used to partition particles into clusters,and the center of each cluster gives the state estimation of an individual *** results indicate that the proposed algorithm outperforms the standard clustering approach using the k-means algorithm,achieving higher accuracy and shorter computational time.

关键词： probability hypothesis density state estimation particle filter multi-target tracking

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基于平稳小波变换的相空间重构方法

振动．测试与诊断 2012年第6期32卷 981-985,1038页

作者：章立军张利欣阳建宏黎敏北京科技大学国家材料服役安全科学中心北京100083 北京科技大学机械工程学院北京100083

针对非线性信号特征提取问题,提出一种基于平稳小波变换的相空间重构方法。对信号进行多层平稳小波分解,利用得到的不同尺度小波系数进行相空间重构,通过局部切空间变换方法提取蕴涵在相空间高维数据集中信号的低维形态特征。仿真试验... 详细信息

针对非线性信号特征提取问题,提出一种基于平稳小波变换的相空间重构方法。对信号进行多层平稳小波分解,利用得到的不同尺度小波系数进行相空间重构,通过局部切空间变换方法提取蕴涵在相空间高维数据集中信号的低维形态特征。仿真试验结果表明,非线性信号经过平稳小波变换后,吸引子轨迹与原有轨迹具有相似的结构。利用局部切空间变换可获得带有高斯白噪声的非线性信号的低维形态特征,该低维形态特征与原有非线性信号的吸引子轨迹相似。这种相空间重构方法较传统的方法具有一定的优势,可以用于提取含有噪声的机械振动信号的故障特征。

关键词：非线性平稳小波变换相空间重构降维低维形态特征

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IGS产品在GPS时间比对中的应用

天文学报 2004年第4期45卷 428-436页

作者：高玉平中国科学院国家授时中心西安710600

在利用GPS CV(GPS Common View)技术进行高精度时间比对时,电离层和卫星位置误差对观测到的卫星信号的影响是不容忽视的,需要对它进行精确的估计和改正.讨论IGS精密星历和CODE全球总电子含量图(TEC MAPs)在GPS时间传递中的应用.计算结... 详细信息

在利用GPS CV(GPS Common View)技术进行高精度时间比对时,电离层和卫星位置误差对观测到的卫星信号的影响是不容忽视的,需要对它进行精确的估计和改正.讨论IGS精密星历和CODE全球总电子含量图(TEC MAPs)在GPS时间传递中的应用.计算结果表明,采用IGS产品可有效提高单站定时和远距离时间传递的精度.

关键词： IGS GPS 时间比对总电子含量电离层改正观测卫星信号单站星历

Pathways of birnessite formation in alkali medium

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Science China Earth Sciences 2005年第9期48卷 1438-1451页

作者： FENG Xionghan1, TAN Wenfeng1, LIU Fan1, HUANG Qiaoyun1 & LIU Xiangwen2 1. College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China 2. Testing center, China University of Geosciences, Wuhan 430074, China College of Resources and Environment Huazhong Agricultural University Wuhan China Testing center China University of Geosciences Wuhan China

Birnessite is a common weathering and oxidation product of manganese-bearing rocks. An O2 oxidation procedure of Mn(OH)2 in the alkali medium has been used to synthesize birnessite. Fast and powder X-ray diffraction (XRD), transmission electron microscopy (TEM), electron diffraction (ED), energy dispersed X-ray analysis (EDAX), infrared spectroscopy (IR) techniques and chemical composition analysis, Eh-pH equilibrium diagram approaches were employed to investigate the reaction process and pathways of birnessite formation. Results showed that the process of the birnessite formation could be divided into four stages: (1) forma- tion stage for hausmannite and feitknechtite, (2) stage of transformation of hausmannite and feitknechtite to buserite, (3) buserite crystal growing stage, and (4) stage of conversion of buser- ite into birnessite. Mn(OH)2 was mainly present as amorphous state only for a short initial time of oxidation reaction. In the oxidation process, buserite formed following two pathways by recrys- tallization after dissolution of the intermediates, and the transformations of the minerals de- pended on the Eh determined by the dissolved O2 concentration on their surfaces. The results are fundamental in further exploration on the mechanism of birnessite formation in the alkali medium. A great practical significance would also be expected with respect to the areas of mate- rial sciences.

关键词： birnessite, pathway of formation, reaction process, Eh-pH diagram, hausmannite, feitknechtite.

Precise time Measurement System Based on GPIB

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Precise Time Measurement System Based on GPIB

Virus rejection with two model human enteric viruses in membrane bioreactor system

ICEMI'2005第七届国际电子测量与仪器学术会议

作者： Dong Shaowu1 2 Qi Yi1 1national time service center Chinese Academy of Sciences 3 Shuyuan Dong lu Lintong Xi’an 710600 Shaanxi CHINA 2Graduate School of the Chinese Academy of Sciences Beijing 100039

In this paper, a precise time measurement system based on GPIB interface was introduced. Personal computer combined with GPIB card is acts as the controller in the precise time comparison system, its

关键词： time Measurement GPIB.

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Science China Chemistry 2007年第3期50卷 397-404页

作者： ZHENG Xiang1,2 & LIU JunXin1 1 Research center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China 2 School of Environment & Natural Resources, Renmin University of China, Beijing 100872, China Research center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China School of Environment & Natural Resources Renmin University of China Beijing 100872 China

A membrane bioreactor (MBR) with gravity drain was tested for virus rejection with two coliphages, T4 and f2, which were used as surrogates for human enteric viruses. Virus rejection was investigated by PVDF and PP membrane modules, with the pore sizes of 0.22 and 0.1 μm, respectively. In tap water system, 2.1 lg rejection of coliphage T4 could be achieved by PVDF membrane compared with complete rejection by PP membrane, while for coliphage f2 with smaller diameter, 0.3―0.5 lg rejection of the influent virus was removed by the two membranes. In domestic wastewater system, cake layer and gel layer on the membrane surface changed the cut-off size of the membrane so that there was no significant difference between PP and PVDF for each coliphage. The removal ratios of coliphage T4 and f2 in the MBR were more than 5.5 and 3.0 lg, respectively. Compared with 5.5 lg removal for virus T4 in the MBR system, only 2.1 lg (96.8%―99.9%) removal rate was observed in the conventional activated sludge system with the influent virus concentration fluctuating from 1830 to 57000 PFU/mL. Only 0.8%―22% virus removal was the effect of adsorption to activated sludge, which showed a decreasing tendency with the retention time, while 75%―98% was the effect of virus inactivation by microbial activity. It indicated that the major mechanism of virus removal was not the transfer of viruses from the water phase to the sludge phase but inactivation in the biological treatment process.

关键词： MBR model virus enteric virus inactivation

Sampling Survey and Identification of Races of Soybean Cyst Nematode (Heterodera glycines Ichinohe) in Huang-Huai Valleys

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Journal of Integrative Agriculture 2006年第8期5卷 615-621页

作者： LU Wei-guo1, 2, GAI Jun-yi1 and LI Wei-dong2 1 Soybean Research Institute of Nanjing Agricultural University/national center for Soybean Improvement/national Key Laboratory for Crop Genetics and Germplasm Enhancement, Nanjing 210095, P.R.China 2 Institute of Cotton and Oil Crops, Henan Academy of Agricultural Sciences, Zhengzhou 450002, P.R.China Department of Otolaryngology University Hospital VU P.O. Box 7057 1007 MB Amsterdam The Netherlands Soybean Research Institute of Nanjing Agricultural University/national center for Soybean Improvement/national Key Laboratory for Crop Genetics and Germplasm Enhancement Nanjing 210095 P.R.China

Soybean cyst nematode (SCN Heterodera glycines Ichinohe) is one of the most important nationwide soybean diseases in China. A total of 38 soil specimens or locations in the area was sampled and tested for SCN races during 2001-2003 for the inspection of race distribution in Huang-Huai Valleys. A map of race distribution was constructed according to the data from both the present study and the published reports cited. Three areas, namely, the area of southeast to Jinan in Shangdong Province; the area of northern Henan Province and its border region to south of Hebei Province; and the area of Luohe, Zhoukou of Henan Province and Fuyang of Anhui Province mainly infested with Race 1 were identified. Race 4 was predominant in Shanxi Province, Beijing and the adjacent area of Henan, Shandong, and Anhui provinces, and the delta of Huanghe River in Shandong Province. Race 2 was mainly found in Liaocheng, Dezhou of Shangdong Province and Shijiazhuang of Hebei Province, and Jiaozuo and Huojia of Henan Province. Race 7 was distributed in the west part of Jiaodong Peninsula of Shandong Province and Kaifeng, Huaxian, Wenxian of Henan Province. Race 5 was found and scattered in Hebei and Henan Province. Race 9 was found in Shangqiu of Henan Province, which was reported for the first time in China. It can be seen that Race 1 and Race 4 were the two predominant races in Huang-Huai Valleys, and that research should focus on developing resistant cultivars of these races. There might exist other races in an area with some predominant races. The race substitution in the past decade was not obviously found, therefore, the results should be meaningful to future breeding for resistance to SCN in Huang-Huai Valleys.

关键词： soybean (Glycine max (L.) Merr.) Huang-Huai Valleys cyst nematode (Heterodera glycines Ichinohe) race

Photogeneration of the free radicals and singlet oxygen by chrysophanol from rheum

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Science China Chemistry 2004年第5期47卷 381-387页

作者： RAO Jing1,2, XIE Jie1, ZHAO Jingquan1 & ZHU Teng2 1. Key Laboratory of Photochemistry, center for Molecular Science, Institute of Chemistry, The Chinese Academy of Sciences, Beijing 100080, China 2. University of Science and Technology Beijing, Beijing 10083, China Key Laboratory of Photochemistry Center for Molecular Science Institute of Chemistry The Chinese Academy of Sciences Beijing 100080 China

In the current work, chryosphanol (MHAQ) was isolated and purified from rheum, and the photosensitization activities were studied. In nitrogen-saturated DMSO solution, irradia- tion of chryosphanol (MHAQ) with visible light (>430 nm) produced the semiquinone radical anions (MHAQ??), which was intensified significantly by an electron donor NADH, suggesting electron transfer between the excited and ground state photosensitizer molecules. In an air-saturated DMSO solution, superoxide radical anions (O2 ), trapped by DMPO, were detected. ?? It was proved that O2 was not originated from the singlet oxygen (1O2) but dependent on DMPO, ?? chrysophanol, oxygen and the irradiation time. The singlet oxygen and OH could also be pro- ? duced by the photosensitization of the photosensitizer. These suggest that chrysophanol pos- sesses the photosensitization activity via Type I mechanism and Type II mechanism. To evaluate the photosensitization activities of MHAQ, emodin and mixed anthraquinone derivatives ex- tracted from rheum, the relative productivities of O2 were estimated to be 1.8, 1.1 and 1.0 re- ?? spectively and the quantum yields for singlet oxygen to be 0.36, 0.53 and 0.14 respectively. Therefore, these low-cost pigments may be potentially used as phototherapeutic medicine for some kind of vascular diseases or photo-activated pesticides.

关键词： chrysophanol, ESR, semiquinone radical anions, superoxide radical anions, hydroxyl radical, singlet oxygen.

Thermal transformation of δ-MnO2 nanoflowers studied by in-situ TEM

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中国科学:化学 2012年第11期 1650-1652页

作者： SUN YuGang 1,LIU YuZi 1,TRUONG Tu T.1 & REN Yang 2 1 center for Nanoscale Materials,Argonne national Laboratory,9700 South Cass Avenue,Argonne,Illinois 60439,US2 X-Ray Science Division,Argonne national Laboratory,9700 South Cass Avenue,Argonne,Illinois 60439,US

In-situ transmission electron microscopy in combination with a heating stage has been employed to real-time monitor variations of-phase MnO2 nanoflowers in terms of their morphology and crystalline structures upon thermal annealing at elevated temperatures up to ～665 °***-temperature annealing drives the diffusion of the small δ-MnO2 nanocrystallites within short distances less than 15 nm and the fusion of the adjacent δ-MnO2 nanocrystallites,leading to the formation of larger crystalline domains including highly crystalline *** annealed nanoflowers remain their overall flower-like morphology while they are converted to α-*** preferred transformation of the-MnO 2 to the α-MnO2 can be ascribed to the close lattice spacing of most crystalline lattices between δ-MnO2 and α-MnO2,that might lead to a possible epitaxial growth of δ-MnO2 lattices on the α-MnO2 lattices during the thermal annealing process.

关键词： δ-MnO2 nanoflowers -MnO2 thermal annealing in-situ TEM mechanism study