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The gravity wave instability induced by photochemistry in summer polar mesopause region

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chinese science Bulletin 2000年第3期45卷 267-272页

作者： center for Space science and Applied Research, chinese academy of sciences, Beijing 100080, china Laboratory of Numeric Study of Heliospheric {4., chinese academy of sciences, Beijing 100080, china center for Space science and Applied Research Chinese Academy of Sciences Beijing China Laboratory of Numeric Study of Heliospheric physics Chinese Academy of Sciences Beijing China

The effect of diabatic process due to the photochemical heating and cooling on the gravity wave propagation in middle atmosphere is studied. A linear gravity wave model which considers the diabatic process is established. The unstable region and the growth rate of the gravity wave caused by photochemistry are calculated. And the comparison between the model and the adiabatic gravity wave theory of pure dynamics is made. The results indicate that the photochemical heating process can induce the instability of gravity wave at mesopause. The intensity of the instability becomes stronger as the temperature decreases. The temperature feature and the altitude characteristics of the instability are consistent with the observation. Therefore, the instability of the gravity wave induced by photochemistry may be an important mechanism in polar mesopause region in summer.

关键词： photochemistry instability gravity wave growth rate.

Lepton flavor violating Z-boson decays at GigaZ as a probe of supersymmetry

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science china(physics,Mechanics & Astronomy) 2010年第11期53卷 1949-1952页

作者： YANG JinMin 1,2 1 Department of physics,Henan Normal University,Xinxiang 4.3007,china 2 Institute of theoretical physics,{4.,Beijing 100190,china Department of physics Henan Normal University Xinxiang China Institute of theoretical physics Chinese Academy of Sciences Beijing China

This paper briefly reviews the lepton flavor violating Z-decays at GigaZ as a probe of supersymmetry by focusing on Z → i j in two representative supersymmetric models: the minimal supersymmetric model without R-parity and the supersymmetric seesaw *** work concludes that under the current experimental constraints from LEP and i → j γ,these rare decays can still be enhanced to reach the sensitivity of the ***,supersymmetry can be probed via these decays at GigaZ.

关键词： Z-decay GigaZ supersymmetry

Patterns of platinum-group elements in mantle peridotite, granulite xenoliths and basalt in Hannuoba

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chinese science Bulletin 1999年第18期44卷 1676-1681页

作者： CHU Xuelei, LI Xiaolin, XU Jiuhua and LIU Jianming1. The Research center of Mineral Resources Exploration , chinese academy of sciences , Beijing 100101, china 2. Institute of Geology , chinese academy of sciences , Beijing 100029, china 3. Institute of High Energy physics , chinese academy of sciences , Beijing 100817 , china 4. Beijing University of science and Engineering , Beijing 100083, china Corresponding author The Research center of Mineral Resources Exploration Chinese Academy of Sciences Beijing China Institute of Geology Chinese Academy of Sciences Beijing China Institute of High Energy physics Chinese Academy of Sciences Beijing China Beijing University of science and Engineering Beijing China

Neutron activation analysis after preconcentration of nickel sulfide fire assay was used in measurement of Ru, Ph, Pd, Os, Ir, Pt (i.e. PGE elements) and Au concentrations for basalt, mantle and granulite xenoliths in Hannuoba. The chondrite- and primitive mantle-normalized PGE patterns generally exhibit flat (for Iherzolite), negative slope (for harzburgite),

关键词： mantle xenolith granulite xenolith basalt platinum-group element Hannuoba.

From quantum spectra to classical orbits: Varying rectangular billiards

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Progress in Natural science:Materials International 2008年第8期18卷 927-930页

作者： Jun Lu * Department of Foundational science, Beijing Union University, Beijing 100101, china Institute of theoretical physics, {4., Beijing 100080, china Department of Foundational science Beijing Union University Beijing 100101 China Institute of theoretical physics Chinese Academy of Sciences Beijing 100080 China

The quantum-spectrum function is introduced by means of the eigenvalues and the eigenfunctions in the system of varying rectangular billiards. It is found that the Fourier transform of the quantum-spectrum function corresponds with the classical orbits in the system. These results give new evidence about the classical-quantum correspondence.

关键词： Quantum spectrum Classical-quantum correspondence Semiclassical physics

Compression behavior of Zr_(4.)Ti_(14.Cu_(12.5)Ni_(10)Be_(22.5) bulk metallic glass up to 24.GPa

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science china(physics,Mechanics & Astronomy) 2005年第3期48卷 319-324页

作者： LI Gong 1, 2 , ZHAN Zaiji 2 , LIU Jing 3 , YUN Jinku 1 , SUN Liling 2 , LIU Riping 1 , ZHANG Jun 2 & WANG Wenkui 1, 2 1. Key Laboratory of Metastable Materials science and Technology, Yanshan University, Qinhuangdao 066004. china 2. center for Condensed Matter physics, Institute of physics, chinese academy of sciences, Beijing 100080, china 3. BSRF, Institute of High Energy physics, chinese academy of sciences, Beijing 100039, china Key Laboratory of Metastable Materials science and Technology Yanshan University Qinhuangdao China center for Condensed Matter physics Institute of Physics Chinese Academy of Sciences Beijing China BSRF Institute of High Energy Physics Chinese Academy of Sciences Beijing China

The compression of a Zr4.Ti14.u12.5Ni10Be22.5 bulk metallic glass (BMG) is investigated at room temperature up to 24.GPa using in-situ high pressure energy dispersive X-ray diffraction with a synchrotron radiation source. The pressure-induced structural relaxation is exhibited. It is found that below about 8 GPa, the existence of excess free volume contributes to the rapid structural relaxation, which gives rise to the rapid volumetric change, and the structural relaxation results in the structural stiffness under higher pressure.

关键词： bulk metallic glass, high pressure, structural relaxation, synchrotron radiation.

Finding Signals for Plant Promoters

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Genomics, Proteomics & Bioinformatics 2003年第1期1卷 68-73页

作者： Weimou ZhengInstitute of theoretical physics, chinese academy of sciences, Beijing 100080, china Beijing GenomicsInstitute, chinese academy of sciences, Beijing 101300, china Institute of theoretical physics Chinese Academy of Sciences Beijing 100080 China Beijing Genomics Institute Chinese Academy of Sciences Beijing 101300 China

The strongest signal of plant promoter is searched with the model of single motif with two types. It turns out that the dominant type is the TATA-box. The other type may be called TATA-less signal, and may be used in gene finders for promoter recognition. While the TATA signals are very close for the monocot and the dicot, their TATA-less signals are significantly different. A general and flexible multi-motif model is also proposed for promoter analysis based on dynamic programming. By extending the Gibbs sampler to the dynamic programming and introducing temperature, an efficient algorithm is developed for searching signals in plant promoters.

关键词： for on is as et Pro Finding Signals for Plant Promoters been of into

Observation results of relativistic electrons detected by Fengyun-1 satellite and analysis of relativistic electron enhancement (REE) events

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science china(physics,Mechanics & Astronomy) 2008年第12期51卷 1947-1956页

作者： YANG XiaoChao1,2↑ & WANG ShiJin1 1 center for Space science and Applied Research, chinese academy of sciences, Beijing 100190, china 2 Graduate University of chinese academy of sciences, Beijing 10004., china center for Space science and Applied Research Chinese Academy of Sciences Beijing China Graduate University of chinese academy of sciences Beijing China

The space particle component detector on Fengyun-1 satellite which works at the sun-synchronous orbit of about 870 km altitude has detected relativistic electrons for a long time. In comparison with the SAMPEX satellite observations during 1999–2004. the relativistic electron data from Fengyun-1 satellite from June 1999 to 2005 are used to analyze the relativistic electron enhancement (REE) events at the low earth orbit, and the possible correlation among REE events at the low earth orbit, high-speed solar wind and geomagnetic storms is discussed. The statistical result presents that 4. REE events are found in total during this time period, and the strong REE events with the maximum daily average flux > 4.0 cm?2·srt-1·s?1 occur mostly during the transition period from solar maximum to solar minimum. Among these 4. REE events, four strong REE events last a longer time period from 26-to 51-day and correlate closely with high speed solar wind and strong geomagnetic storms. Meanwhile, several strong geomagnetic storms occur continuously before these REE events, and these continuous geomagnetic storms would be an important factor causing these long-lasting strong REE events. The correlation analysis for overall 4. events indicates that the strength of the REE events correlates with the solar wind speed and the strength of the geomagnetic storm, and the correlation for strong REE events is much stronger than that for weak REE events.

关键词： relativistic electron enhancement low earth orbit high-speed solar wind geomagnetic storm

fMRI time series analysis based on stationary wavelet and spectrum analysis

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Progress in Natural science:Materials International 2006年第11期16卷 1171-1176页

作者： ZHI Lianhe~ 1,2,3 , ZHAO Xia~4. SHAN Baoci~1**, PENG Silong~5, YAN Qiang~1, YUAN Xiuli~1 and TANG Xiaowei~ 1,6 (1. Key Laboratory of Nuclear Analysis Techniques, Institute of High Energy physics, chinese academy of sciences, Beijing 10004., china 2. Graduate School of chinese academy of sciences, Beijing 10004., china 3. Department of physics, Zhoukou Normal University, Zhoukou 4.6100, china 4. Research Imaging center, University of Texas Health science center, San Antonio, Texas 78229, USA 5. National ASIC Design and Engineering center, Institute of Automation, chinese academy of sciences, Beijing 10004., china 6. Department of physics, Zhejiang University, Hangzhou 310027, china) Key Laboratory of Nuclear Analysis Techniques Institute of High Energy Physics Chinese Academy of Sciences Beijing 100049 China Graduate School of chinese academy of sciences Beijing 100049 China Department of physics Zhoukou Normal University Zhoukou 466100 China Research Imaging center University of Texas Health Science Center San Antonio TX 78229 United States National ASIC Design and Engineering center Institute of Automation Chinese Academy of Sciences Beijing 100049 China Department of physics Zhejiang University Hangzhou 310027 China

The low signal to noise ratio (SNR) of functional MRI (fMRI) prefers more sensitive data analysis methods. Based on stationary wavelet transform and spectrum analysis, a new method with high detective sensitivity was developed for analyzing fMRI time series, which does not require any prior assumption of the characteristics of noises. In the proposed method, every component of fMRI time series in the different time-frequency scales of stationary wavelet transform was discerned by the spectrum analysis, then the components from noises were removed using the stationary wavelet transform, finally the components of real brain activation were detected by cross-correlation analysis. The results obtained from both simulated and in vivo visual experiments illustrated that the proposed method has much higher sensitivity than the traditional cross-correlation method.

关键词： fMRI stationary wavelet transform spectrum analysis data analysis.

Response synchronization: New progress in brain-visual information processing

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chinese science Bulletin 1999年第16期44卷 1447-1458页

作者： ZHAO Songnian, XIONG Xiaoyun, YAO Guozheng and GUO Aike1. State Key Laboratory of Atmospheric Boundary Layer physics and Atmospheric Chemistry , Institute of Atmospheric physics , chinese academy of sciences , Beijing 100029, china 2. Commission of the National Natural {4. Foundation of china , Beijing 100083, china 3. The center of Information {4. , Peking University, Beijing 100871, china 4. Open Laboratory of Visual Information Processing , Institute of Biophysics , chinese academy of sciences , Beijing 100101, china State Key Laboratory of Atmospheric Boundary Layer physics and Atmospheric Chemistry Institute of Atmospheric Physics Chinese Academy of Sciences Beijing China Commission of the National Natural science Foundation of china Beijing China The center of Information science Peking University Beijing China Open Laboratory of Visual Information Processing Institute of Biophysics Chinese Academy of Sciences Beijing China

Studies on brain-vision have entered a new stage, after the stimulus-induced y synchronized oscillation of neuron group activities have been discovered in cat primary visual cortex. Naturally, how to understand the visual system became a very important methodological problem. From aspects such as information processing, nonlinear dynamics and neuronal network, some primary problems in vision studies have been deeply discussed, which are

关键词： neuron group (neural population) synchro-oscillation computational theory of vision response synchroniza-tion.