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Male spike strobiles with Gnetum affinity from the Early Cretaceous in western Liaoning,Northeast china

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Journal of Systematics and Evolution 2009年第2期47卷 93-102页

作者： 1,2Shuang-Xing GUO 3Jin-Geng SHA 4Li-Zeng BIAN 5Yin-Long QIU 1(Department of Palaeobotany and Palynology,nanjing institute of Geology and Paleontology,chinese academy of sciences,nanjing 210008,china) 2(laboratory of Biodiversity and Biogeography,Kunming institute of Botany,chinese academy of sciences,Kunming 650204,china) 3(State key laboratory of Palaeobiology and Stratigraphy,nanjing institute of Geology and Palaeontology,chinese academy of sciences,nanjing 210008,china) 4(College of Earth sciences,nanjing University,nanjing 210093,china) 5(Department of Ecology & Evolutionary Biology,The University Herbarium,University of Michigan,Ann Arbor,MI 48109-1048,USA) Department of Palaeobotany and Palynology Nanjing Institute of Geology and Paleontology Chinese Academy of Sciences Nanjing 210008 China laboratory of Biodiversity and Biogeography Kunming Institute of Botany Chinese Academy of Sciences Kunming 650204 China State key laboratory of Palaeobiology and Stratigraphy Nanjing Institute of Geology and Palaeontology Chinese Academy of Sciences Nanjing 210008 China College of Earth sciences Nanjing University Nanjing 210093 China Department of Ecology & Evolutionary Biology The University Herbarium University of Michigan Ann Arbor MI 48109–1048 USA

A fossil with Gnetum affinity was found in the Jianshangou Member(Barremian Age) of the Yixian Formation(Lower Cretaceous Epoch) of the Jehol Group in western Liaoning,northeastern *** single fossil specimen is represented by both elongate-cylindrical male spike strobiles which borne within a nodal bract of cauliflorous *** spike strobiles have apparent nodes,invisible internodes,and numerous verticillate involucral *** microsporangiate units within involucral collars are not *** male spike strobiles with verticillate involucral collars occur exclusively in Gnetum;hence,the fossil strobiles are attributed to a new taxon,Khitania columnispicata gen.& ***.,being closely related to *** general isotopic dating suggests an age of Barremian,ca.125-122 million years(Myr) ago for the Jianshangou *** palaeoecological and palaeoclimatic inference based on the compositions of flora and fauna,and lithological characters of the fossil locality suggests that the fossil plants grew in a subtropical mesophytic forest and under a warmer *** remains of male spike strobiles are the first record of gnetalean *** documents the evolution of the distinct gnetoid morphology and indicates a wider range of distribution of Gnetaceae in the Early Cretaceous than present day.

关键词： biogeography Early Cretaceous Gnetum affinity male spike strobiles northeastern china

Study on growth and properties of novel γ-LiAlO_2 substrate

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Science china(Technological sciences) 2006年第2期49卷 188-193页

作者： ZOU Jun1,2, ZHOU Shengming1, XU Jun1 & ZHANG Rong3 1. Shanghai institute of optics and Fine Mechanics, chinese academy of sciences, Shanghai 201800, china 2. Graduate School of chinese academy of sciences, Beijing 100039, china 3. laboratory of Solid State Microstructures and Department of Physics, nanjing University, nanjing 210093, china Shanghai institute of optics and Fine Mechanics Chinese Academy of Sciences Shanghai China Graduate School of chinese academy of sciences Beijing China laboratory of Solid State Microstructures and Department of Physics Nanjing University Nanjing China

Transparent γ-LiAlO2 single crystal has been grown by Temperature Gradient technique. The surface of the wafer annealed in O2-atmosphere at 1100°C for 70 h became opaque and Li-poor phase (LiAl5O8); while, that annealed in Li-rich atmosphere kept transparent and smooth. The full-width at half maximum value dropped to 30 arcsecs when the wafer was annealed in Li-rich atmosphere. That annealed in O2-atmosphere increased to 78 arcsec. Compared with absorption spectra, we can conclude that the 196 nm absorption peak was caused by Li vacancies and the 736 nm peak was caused by O vacancies.

关键词： γ-LiAlO2 crystal, scanning electron micrograph (SEM), absorption spectra.

Chronology of Holocene lacustrine sediments in Co Ngoin, central Tibetan Plateau

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Science china Earth sciences 2006年第9期49卷 991-1001页

作者： WU Yanhong1, WANG Sumin1& HOU Xinhua1,3 1. key laboratory of Lake Sedimentation and Environment, nanjing institute of Geography and Limnology, chinese academy of sciences, nanjing 210008, china 2. institute of Tibetan Plateau Research, chinese academy of sciences, Beijing 10085, china 3. Graduate University of chinese academy of sciences, Beijing 100039, china key laboratory of Lake Sedimentation and Environment Nanjing Institute of Geography and Limnology Chinese Academy of Sciences Nanjing China institute of Tibetan Plateau Research Chinese Academy of Sciences Beijing China Graduate University of chinese academy of sciences Beijing China

Chronology is the basis for using lacustrine sediments to reconstruct the history of en-vironmental change. Radioactive-nuclides such as 14C, 210Pb and 137Cs dating are mainly used to establish the chronology for recent several ten thousand years. Because of being mixed with “dead carbon”, the measured 14C age is always older than the actual age which is recognized as “reservoir effect”. Cs is a kind of active metal element, and easy to migrate vertically in the sediment that leads to the error of the time marker. 210Pb dating should make sure to select CIC model or CRS model. On the Tibetan Plateau, most of the lakes are alkaline closed lake where Cs is more moveable in the sediment and the reservoir effect caused by “dead carbon” on 14C dating is stronger. Based on the analysis on results of 14C, 210Pb and 137Cs of the lacustrine sediments from Co Ngoin, central Tibetan Plateau, we use the simple regression method to re-calculate the 14C calendar ages, and establish the time sequence for cores CE-1 and CE-2 with result of 210Pb CRS model for the upper 35 cm and re-calculated 14C calendar age for sediments bellow 35 cm. Since 1400 cal. a BP, sedimentation inter-rupted for more than 1000 years. According to this time sequence, variations of environmental proxies confidently reflect the major climatic events in Holocene.

关键词： 14C, 210Pb and 137Cs, chronology, lacustrine sediments, climatic event, Co Ngoin, central Tibetan Plateau.

Wavefront reconstruction algorithm for wavefront sensing based on binary aberration modes

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chinese Physics B 2017年第5期26卷 153-159页

作者：庞博清王帅程涛孔庆峰文良华杨平 key laboratory on Adaptive optics Chinese Academy of Sciences Chengdu 610209 China University of chinese academy of sciences Beijing 100049 China The institute of optics and Electronics Chinese Academy of Sciences Chengdu 610209 China School of Optoelectronic information University of Electronic Science and Technology of China Chengdu 610209 China School of Physics and Electronic Engineering Yibin University Yibin 644000 China

We propose a new algorithm for wavefront sensing based on binary intensity modulation. The algorithm is based on the fact that a wavefront can be expended with a series of orthogonal and binary functions, the Walsh series. We use a spatial light modulator（SLM） to produce different binary-intensity-modulation patterns which are the simple linear transformation of the Walsh series. The optical fields under different binary-intensity-modulation patterns are detected with a *** relationships between the incident wavefront modulated with the patterns and their optical fields are built to determinate the coefficients of the Walsh series. More detailed and strict relationship equations are established with the algorithm by adding new modulation patterns according to the properties of the Walsh functions. An exact value can be acquired by solving the equations. Finally, with the help of phase unwrapping and smoothing, the wavefront can be reconstructed. The advantage of the algorithm is providing an analytical solution for the coefficients of the Walsh series to reconstruct the wavefront. The simulation experiments are presented and the effectiveness of the algorithm is demonstrated.

关键词： wavefront aberration Walsh modulated reconstructed optics incident smoothing Zernike modulator

Preparation and Characterization of Sol-gel Derived CH_3SiO_(3/2)-SiO_2 Thick Film

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Journal of Materials Science & technology 1998年第6期14卷 523-526页

作者： Bing CAO and Congshan ZHU(Shanghai institute of optics and Fine Mechanics, chinese academy of sciences, Shanghai 201800, china) Shanghai institute of optics and Fine Mechanics Chinese Academy of Sciences Shanghai 201800 China

A large size CH3SiO3/2-SiO2 self sustained film with the thickness ranging from 50 to 1000 μm was prepared through sol-gel method by adopting CH3Si(OC2H5)3 and Si(OC2H5) as *** this paper, the preparation processes of this thick film are discussed in detail and XRD technique was adopted for the identification of oligomer solution. Also, IR and AFM techniques were used to investigate the film structure and surface morphology

关键词： Preparation and Characterization of Sol-gel Derived CH3SiO MTES CH

Using Fractal Function Auto-correlative Method to Confirm Fractal Dimension of Function Graph

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chinese Journal of Lasers 1999年第2期8卷 54-57页

作者： FAN Chengyu (Anhui institute of optics and Fine Mechanics, The chinese academy of sciences, Hefei 230031, china) 中科院安徽光学精密机械所安徽合肥 230031

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１ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅｈｙｐｏｔｈｅｓｉｓｏｆａｓｔａｔｉｓｔｉｃａｌｙｌｏｃａｌｙｉｓｏｔｒｏｐｉｃｈｏｍｏｇｅｎｅｏｕｓｔｕｒｂｕｌｅｎｔｆｉｅｌｄｗａｓｔｈｅｂａｓｅｏｆＫｏｌｍｏｇｏｒｏｖ’ｓｍｏｄｅｌ［１］．Ｔｈｅｓｅｃｏｎｄｏ...

关键词： function graph fractal dimension power spectrum

Seasonal variation of potential denitrification rates of surface sediment from Meiliang Bay, Taihu Lake, china

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Journal of Environmental sciences 2010年第7期22卷 961-967页

作者： Jicheng Zhong, Chengxin Fan, Guofeng Liu, Lei Zhang, Jingge Shang, Xiaozhi GuState key laboratory of Lake Science and Environment, nanjing institute of Geography and Limnology, chinese academy of sciences, nanjing 210008, china. State key laboratory of Lake Science and Environment Nanjing Institute of Geography and Limnology Chinese Academy of Sciences Nanjing 210008 China

The regulatory effects of environmental factors on denitrification were studied in the sediments of Meiliang Bay, Talhu Lake, in a monthly sampling campaign over a one-year period. Denitrification rates were measured in slurries of field samples and enrichment experiments using the acetylene inhibition technique. Sediment denitrification rates in inner bay and outer bay ranged from 2.8 to 51.5 nmol N2/（g dw （dry weight）·hr） and from 1.5 to 81.1 nmol N2/（g dw·hr）, respectively. Sediment denitrification rates were greatest in the spring and lowest in the summer and early autumn, due primarily to seasonal differences in nitrate concentration and water temperature. For each site, positive and linear relationships were regularly observed between denitrification rate and water column nitrate concentration. Of various environmental factors on denitrification that we assessed, nitrate was determined to be the key factor limiting denitrification rates in the sediments of Meiliang Bay. In addition, at the two sites denitrification rates were also regulated by temperature. The addition of organic substrates had no significant effect on denitrification rate, indicating that sediment denitrification was not limited by organic carbon availability in the sediments. Nitrate in the water column was depleted during summer and early autumn, and this suppressed effective removal of nitrogen from Taihu Lake by denitrification.

关键词： denitrification sediment environmental factors Taihu Lake

One-step estimation for varying coefficient models

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Science china Mathematics 2005年第2期48卷 198-213页

作者： TANG Qingguo & WANG Jinde Department of Mathematics, nanjing University, nanjing 210093, china institute of sciences, PLA University of Science and technology, nanjing 210007, china Department of Mathematics Nanjing University Nanjing China institute of sciences PLA University of Science and Technology Nanjing China

A one-step method is proposed to estimate the unknown functions in the varying coefficient models, in which the unknown functions admit different degrees of smoothness. In this method polynomials of different orders are used to approximate unknown functions with different degrees of smoothness. As only one minimization operation is employed, the required computation burden is much less than that required by the existing two-step estimation method. It is shown that the one-step estimators also achieve the optimal convergence rate. Moreover this property is obtained under conditions milder than that imposed in the two-step estimation method. More importantly, as only one minimization operation is employed, the full asymptotic properties, not only the asymptotic bias and variance, but also the asymptotic distributions of the estimators can be derived. The asymptotic distribution results will play a key role for making statistical inference.

关键词： varying coefficient model, one-step estimation, asymptotic distribution, optimal convergence rate.

Constraints of authigenic carbonates on trace elements (Sr,Mg) of lacustrine ostracod shells in paleoenviron-ment reconstruction and its mechanism

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Science china Earth sciences 2008年第5期51卷 654-664页

作者： HU Guang1,2, JIN ZhangDong1 & ZHANG Fei3 1 State key laboratory of Loess and Quaternary Geology, institute of Earth Environment, chinese academy of sciences, Xi’an 710075, china 2 Graduate University of the chinese academy of sciences, Beijing 100049, china 3 College of Resources and Environmental Science, nanjing Agricultural University, nanjing 210095, china State key laboratory of Loess and Quaternary Geology Institute of Earth Environment Chinese Academy of Sciences Xi’an China Graduate University of the chinese academy of sciences Beijing China College of Resources and Environmental Science Nanjing Agricultural University Nanjing China

Molar ratios of Mg/Ca and Sr/Ca were measured in two species of ostracod shells preserved in the upper core (15–55 m) of the Hequing Basin in Yunnan Province, southwest china. By correlating the molar ratios between Mg/Ca and Sr/Ca and comparing them with Sr concentrations of the sediments, we suggested that: (1) the molar Mg/Ca and Sr/Ca ratio variations in respective ostracod primo reflected the changes in its ambient water composition and ecology; (2) the molar Sr/Ca ratios responded better to the salinity change linearly than Mg/Ca without aragonite precipitation in the system, and otherwise there was no linear relation between them; and (3) the molar Sr/Ca ratios were mainly controlled by salinity and authigenic carbonate precipitation, whereas the molar Mg/Ca ratios were related to both salinity and temperature. In fact, the rate of ostracod growth owing to temperature controls the fluctuation of Mg/Ca in shells. Here, more attentions should be paid to the constraint of authigenic mineral precipitation processes on the trace elements in ostracod shells and to the correlation between these trace elements in biogenic carbonates and compositions of the sediments in systems and in future in vitro experiments.

关键词： ostracod shell molar Sr/Ca ratio molar Mg/Ca ratio environmental response Heqing Basin