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Alkaline phosphatase activity and the phosphorus mineralization rate of Lake Taihu

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Science china Earth sciences 2006年第Z1期49卷 176-185页

作者： GAO Guang, ZHU Guangwei, QIN Boqiang, CHEN Jun & WANG Ke nanjing institute of Geography & Limnology,{2., nanjing 2.0008, china Hohai University, nanjing 2.0098, china nanjing institute of Geography & Limnology Chinese Academy of Sciences Nanjing China Hohai University Nanjing China

The phosphorus fractions, the alkaline phosphatase activity (APA) and other water chemical parameters were concomitantly monitored from April 2.03 to October 2.04 in different ecotype sites of Lake Taihu. During the stages of algae growth, the phosphorus fractions and their relationships with APA in different ecotype sites were discussed and the phosphorus mineralization rate was calculated. In the water of Lake Taihu, most of the phosphorus (70.2.) could be attributed to the suspended particulate phosphorus, while the dissolved reactive phosphorus (DRP) seems to contribute less than 7%. About 58% of the total phosphorus, however, can be hydrolyzed as inorganic phosphate to compensate for phosphorus deficiency of algae and bacteria growth. During the different algae growth stages, the APA and its Kinetic parameters were varied significantly between different ecotype sites of Lake Taihu. This trend is also visible by comparing the phosphorus mineralization rate,and the most rapidly phosphorus turnover time is only several minutes. The fast recycle of phosphorus can, to some extent, be explained that the phosphorus source of algal blooms. The phytoplankton seems to compensate for phosphorus deficiency by using the alkaline phosphatase to hydrolyze phosphomonoesters.

关键词： Lake Taihu, alkaline phosphatase, kinetic parameters, phosphorus, mineralization rate.

Quantitative Relationship Between Land Use and Phosphorus Discharge in Subtropical Hilly Regions of china

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Pedosphere 2003年第1期13卷 67-74页

作者： YANG JINLING and ZHANG GANLINinstitute of Soil Science, the chinese academy of sciences,{2. (china) institute of Soil Science the Chinese Academy of Sciences Nanjing 210008

The increase of phosphorus concentration is a crucial factor causing the eutrophication of water body,while land use has an important impact on agricultural non-point sources (NPS) phosphorus discharge. Sevensites controlling the water in four sub-watersheds and the main exit of the Meicun Watershed of XuanchengCounty, Anhui Province, were investigated by dynamic monitoring of stream water and nutrient discharge,integrating interpretation of aerial image and GIS analysis to find out how the land use affects phosphorusloss with stream water in typical agriculture-forest watershed in subtropical china. These monitored sitesare different in structure of land use. Phosphorus concentration of the stream water was analyzed everyweek and at the next day of rainfall. The velocity of flow was measured by kinemometer to calculatethe runoff flux and phosphorus discharge. The results showed that the runoff flux and the discharges ofdissolved phosphorus (DP), particle-associated phosphorus (PAP) and total phosphorus (TP) had significantexponential relationships with the area percentages of forest, pond and paddy field. There existed a significantlinear relationship between the TP and PAP concentrations in stream water and the area percentages of forest,pond and paddy field, and the discharge of PAP was also significantly linearly correlated with the dischargeof suspended soil particles. There was a logarithmic linear relationship between DP and PAP discharges. Thestudy indicated that the adjustment of land use patterns and construction of ecologically sound landscapewould be an important measure to reduce the runoff discharge of phosphorus. The results would be veryuseful in building the best management practices (BMPs) of agricultural watershed in subtropics.

关键词： land use phosphorus runoff watershed

Study on the simulation of transparency of Lake Taihu under different hydrodynamic conditions

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Science china Earth sciences 2006年第Z1期49卷 162-175页

作者： PANG Yong, LI Yiping & LUO Liancong College of Environmental Science and Engineering, Hohai University, nanjing 2.0098, china nanjing institute of Geography & Limnology, chinese academy of sciences, nanjing 2.0098, china College of Environmental Science and Engineering Hohai University Nanjing China nanjing institute of Geography & Limnology Chinese Academy of Sciences Nanjing China

It was indicated in this study that there were negative relations between the concentrations of suspended solid (SS) and transparency according to the analysis of measured data of Lake Taihu. Their relations in pervious studies were reviewed, which showed that the changes of transparency in Lake Taihu could be reflected by simulating suspended solid concentration (SSC). Measured data showed that the changes of SSC with wind speed were similar at different water *** increased with the increasing of wind speed. Both wave and lake current of Lake Taihu had positive relations with SSC. However, wave was the main factor affecting sediment suspension, while flow took the second place. In this study, a numerical model coupling lake current, wave and SSC of Lake Taihu was developed. In the SS model, the combined effects of wave and current were *** amounts of suspended and deposited sediments near the lake bed surface layer were treated separately. The stochastic characteristics of turbulent flow pulsation near lake beds were also considered, and the start-up conditions of sediment suspension were introduced to the model. The model elucidated the mutual exchange processes between sediment particles in SS and active sediments within and on the bed surface layer. Simulated results showed that lake current had relatively significant effects on the SSC at littoral areas of Lake Taihu, while SSC at the central area of the lake was mainly influenced by wave. The changes of transparency with SSC were simulated for Lake Taihu using this model. Calculated results were validated by measured data with good fitness, which indicated that the model is basically suitable for the simulation and prediction of transparency of Lake Taihu.

关键词： transparency suspended solid hydrodynamlc sediment suspension model.

FOSSIL OPHIUROIDS FROM TONGZIYAN FORMATION(Middle PERMIAN) IN LONGYAN, FUJIAN

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古生物学报 2002年第3期 399-402页

作者： LIAO Zhuo Ting and WANG Xiao Juan (nanjing institute of Geology and {2., the chinese academy of sciences, nanjing 2.0008)

ＳｕｍｍａｒｙＴｈｅｆｏｓｓｉｌｏｐｈｉｕｒｏｉｄｓｄｅｓｃｒｉｂｅｄｉｎｔｈｉｓｐａｐｅｒｗａｓｃｏｌｌｅｃｔｅｄｆｒｏｍｔｈｅＴｏｎｇｚｉｙａｎＦｏｒｍａｔｉｏｎｎｅａｒｔｈｅＫｅｎｇｂｉｎｇＣｏａｌＭｉｎｅｉ... 详细信息

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关键词： echinoderms ophiuroids Middle Permian(Guadalupian) Longyan of Fujian Summary The fossil ophiuroids described in this paper was collected from the Tongziyan Formation near the Kengbing Coal Mine in Longyan. This formation is a suite of pa

Plankton from Early Cambrian black shale series on the Yangtze Platform, and its influences on lithologies

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Progress in Natural Science:Materials International 2003年第10期 57-62页

作者： Andreas BRAUN 1* and CHEN Junyuan 2.1. institute of Paleontology, University of Bonn, Nussallee 8, D 53115 Bonn, Germany 2. nanjing institute of Geology and palaeontology, chinese academy of sciences, nanjing 2.0008, china) institute of Paleontology University of Bonn Nussallee 8 D-53115 Bonn Germany nanjing institute of Geology and {2. Chinese Academy of Sciences Nanjing 210008 China

Black shales, cherts, and associated lithologies in the Early Cambrian of the Yangtze Platform yielded abundant phytoplankton, the earliest well preserved skeletons of zooplankton (radiolarians) and abundant phosphatic ovoid bodies, probably representing fecal pellets, produced by Mesozooplankton grazing on phytoplankton. The oceanic food chain in surface waters is therefore considered to be more complete than known up to now with respect to primary and secondary consumers in the Early Cambrian plankton ecosystem. On the basis of primary sedimentary compositions preserved in phosphorite concretions and chert layers it is shown that biosiliceous sedimentation mixed with organic substance played a significant role within the black shale sequence of the Hetang and Niutitang formations. The resulting lithology corresponds closely in character to the bituminous Alum shale and Lydite sequences of Lower Silurian (Llandoverian) age along northern Gondwana (e.g. Thuringia, Bohemia).

关键词： Black shale Cambrian Plankton Yangtze Platform china.

Crust and uppermost mantle structure of the Ailaoshan-Red River fault from receiver function analysis

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Science china Earth sciences 2006年第10期49卷 1043-1052页

作者： XU Mingjie1, WANG Liangshu1, LIU Jianhua2. ZHONG Kai1, LI Hua1, HU Dezhao1 & XU Zhen1 1. Department of Earth sciences, nanjing University, nanjing 2.0093, china 2. institute of Geology and Geophysics, chinese academy of sciences, Beijing 10002., china Department of Earth sciences Nanjing University Nanjing China institute of Geology and Geophysics Chinese Academy of Sciences Beijing China

S-wave velocity structure beneath the Ailaoshan-Red River fault was obtained from receiver functions by using teleseismic body wave records of broadband digital seismic stations. The average crustal thickness, Vp/Vs ratio and Poisson’s ratio were also estimated. The results indicate that the interface of crust and mantle beneath the Ailaoshan-Red River fault is not a sharp velocity discontinuity but a characteristic transition zone. The velocity increases relatively fast at the depth of Moho and then increases slowly in the uppermost mantle. The average crustal thickness across the fault is 36―37 km on the southwest side and 40―42.km on the northeast side, indicating that the fault cuts the crust. The relatively high Poisson’s ratio (0.2.―0.2.) of the crust implies a high content of mafic materials in the lower crust. Moreover, the lower crust with low velocity could be an ideal position for decoupling between the crust and upper mantle.

关键词： receiver function, Ailaoshan-Red River fault, velocity structure, Poisson's ratio, crust and upper mantle.

Kalligrammatid Lacewings from the Upper Jurassic Daohugou Formation in Inner Mongolia, china

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Acta Geologica Sinica(English Edition) 2003年第2期77卷 141-147页

作者： ZHANG Junfengnanjing institute of Geology and {2., chinese academy of sciences, nanjing, Jiangsu 2.0008, E-mail: jfzhang@*** chinese Acad Sci Nanjing Inst Geol & Palaeontol Nanjing 210008 Jiangsu Peoples R China

A new species, referable to a new genus, is erected, and named the Sinokalligramma jurassicum gen. et sp. nov. It is the second finding of kalligrammatids in the Daohugou Formation. The origin and migration of the family Kalligrammatidae are discussed. The geological age and stratigraphic correlation of the Daohugou and Karabastau Formations are briefly reviewed and reassessed.

关键词： kalligrammatid lacewings new taxa age origin and migration Jurassic Inner Mongolia china

On the knee of Galactic cosmic rays in light of sub-TeV spectral hardenings

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chinese Physics C 2018年第7期42卷 113-122页

作者： Yi-Qing Guo1 2.Qiang Yuan1 3 1. Key Laboratory of Dark Matter and Space Astronomy Purple Mountain Observatory chinese academy of {2. nanjing 2.0008 china 2. Key Laboratory of Particle Astrophysics institute of High Energy Physics Key Laboratory of Dark Matter and Space Astronomy Purple Mountain ObservatoryChinese Academy of Sciences Key Laboratory of Particle Astrophysics Institute of High Energy PhysicsChinese Academy of Sciences School of Astronomy and Space Science University of Science and Technology of China

More than fifty years after the discovery of the knee in the cosmic ray （CR） spectra, its physical origin remains a mystery. This is partly due to the ambiguity of the energy spectra of individual components. Recently, direct measurements from several space experiments found significant spectral hardenings of CR nuclei at ~2.0 GV. A joint modeling of the direct and indirect measurements may help to understand the experimental systematics and the physics of the knee. In this work, we update the phenomenological ＂poly-gonato＂ model to include the spectral hardenings, with a changing spectral index of γ ＋ β·logE. This modification gives a reasonable description of the CR spectra in a wide energy range. However, the fits to different data sets give different results. We find that the fit to the AMS-02.and CREAM data slightly favors a relatively low energy knee of the light components. In such a case, the expected all-particle spectra under-shoot the data, which may require an extra component of CRs. The fits to AMS-02.data and the light component （H＋He） data from the Tibet ASγ/ARGO-YBJ/WFCTA and KASCADE experiments give consistent results with the all-particle spectra. We further propose a possible physical realization of such a ＂modified poly-gonato＂ model of spectral hardenings by means of spatially-dependent diffusion of CRs. We find reasonably good agreement between the model predictions and the data for CR spectra, the secondary-to-primary ratios, and the amplitude of anisotropies.

关键词： cosmic ray knee spectrum propagation

A new method for constructing total energy conservation algorithms

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Progress in Natural Science:Materials International 2003年第1期13卷 59-62页

作者： ZHAO Ying , JI Zhongzhen, YANG Hongwei and WANG Bin (1. LASG, institute of Atmospheric Physics, chinese academy of sciences, Beijing 10002.,{2. 2. institute of Science, PLA University of Science and Technology, nanjing 2.1101,{2.) chinese Acad Sci Inst Atmospher Phys LASG Beijing 100029 Peoples R China PLA Univ Sci & Technol Inst Sci Nanjing 211101 Peoples R China

Abstract Based on a basic rule for the research on numerical methods which requires that the properties of the original problemshould be preserved as much as possible under discretization, a new method for constructing total energy conservation algorithms is pre-sented. By this method, all kinds of implicit schemes with energy conservation laws including many classical conservation schemes can beconstructed from a kind of special function. Also, the concrete criterion for judging total energy conservation schemes is given. Numericaltests show that these new schemes are effective.

关键词： total energy conservation difference scheme quasi-antisymmetric operator norm-preserving operator.