知识网络空间结构演化及对NIS建设的启示——以我国生物技术知识为例   总被引：7，自引：0，他引：7  

汪涛  Ingo LIEFNER  李丹丹 《地理研究》2011,30(10):1861-1872

以重庆维普期刊全文数据库中2000～2009年发表于生物技术领域的合著论文作者信息统计数据为数据源,从省级层面运用UCINET和ArcGIS软件分析知识网络的空间结构特征及其演化规律。近十年来生物技术知识网络经历了由萌芽阶段向扩张阶段和成熟阶段转变的过程,知识的扩散方式由接触扩散为主向等级扩散为主转变,知识交流的密集区...  相似文献   

Magnetic anomalies and rock magnetism of basalts from Reykjanes (SW-Iceland)     

Frank Dietze  Agnes Kontny  Ingo Heyde  Carsten Vahle 《Studia Geophysica et Geodaetica》2011,55(1):109-130

This study presents rock magnetic properties along with magnetic field measurements of different stratigraphic and lithologic basalt units from Reykjanes, the southwestern promontory of the Reykjanes peninsula, where the submarine Reykjanes Ridge passes over into the rift zone of southwestern Iceland. The basaltic fissure eruptions and shield lava of tholeiitic composition (less than 11500 a old) show a high natural remanent magnetization (NRM, J_r) up to 33.6 A/m and high Koenigsberger ratio (Q) up to 52.2 indicating a clear dominance of the NRM compared to the induced part of the magnetization. Pillow basalts and picritic shield lava show distinctly lower J_r values below 10 A/m. Magnetic susceptibility (κ) ranges for all lithologies from 2.5 to 26×10⁻³ SI.  相似文献   

Network configurations and R&D activities of the ICT industry in Suzhou Municipality, China [42(4) (2011) 484–495]     

Y.H. Dennis Wei  Ingo Liefner  Chang-Hong Miao 《Geoforum》2011,42(6):731

  相似文献   

Noble gases in 18 Martian meteorites and angrite Northwest Africa 7812—Exposure ages,trapped gases,and a re‐evaluation of the evidence for solar cosmic ray‐produced neon in shergottites and other achondrites          下载免费PDF全文

R. Wieler  L. Huber  H. Busemann  S. Seiler  I. Leya  C. Maden  J. Masarik  M. M. M. Meier  K. Nagao  R. Trappitsch  A. J. Irving 《Meteoritics & planetary science》2016,51(2):407-428

We present noble gas data for 16 shergottites, 2 nakhlites (NWA 5790, NWA 10153), and 1 angrite (NWA 7812). Noble gas exposure ages of the shergottites fall in the 1–6 Ma range found in previous studies. Three depleted olivine‐phyric shergottites (Tissint, NWA 6162, NWA 7635) have exposure ages of ~1 Ma, in agreement with published data for similar specimens. The exposure age of NWA 10153 (~12.2 Ma) falls in the range of 9–13 Ma reported for other nakhlites. Our preferred age of ~7.3 Ma for NWA 5790 is lower than this range, and it is possible that NWA 5790 represents a distinct ejection event. A Tissint glass sample contains Xe from the Martian atmosphere. Several samples show a remarkably low (²¹Ne/²²Ne)_cos ratio < 0.80, as previously observed in a many shergottites and in various other rare achondrites. This was explained by solar cosmic ray‐produced Ne (SCR Ne) in addition to the commonly found galactic cosmic ray‐produced Ne, implying very low preatmospheric shielding and ablation loss. We revisit this by comparing measured (²¹Ne/²²Ne)_cos ratios with predictions by cosmogenic nuclide production models. Indeed, several shergottites, acalpulcoites/lodranites, angrites (including NWA 7812), and the Brachina‐like meteorite LEW 88763 likely contain SCR Ne, as previously postulated for many of them. The SCR contribution may influence the calculation of exposure ages. One likely reason that SCR nuclides are predominantly detected in meteorites from rare classes is because they usually are analyzed for cosmogenic nuclides even if they had a very small (preatmospheric) mass and hence low ablation loss.  相似文献   

High-magnitude landslide events on a limestone-scarp in central Germany: morphometric characteristics and climatic controls     

Karl-Heinz Schmidt  Ingo Beyer 《Geomorphology》2003,49(3-4):323-342

There are both internal and external controlling factors leading to slope instability and susceptibility to mass movement processes. This paper explores which external climatic variables of different temporal scales influence the occurrence of high-magnitude landslide events. The investigations were focused on the Wellenkalk-cuesta scarp in the Thuringia Basin (Thüringer Becken) in central Germany. The cuesta scarp is composed of a densely jointed limestone caprock (Wellenkalk), and impermeable mudstones and marls of the Upper Bunter Sandstone (Röt) in the lower part of the slope. Mass movements are a typical feature of the Wellenkalk-scarp. The entire scarp slope length (1000 km) has been systematically mapped and investigated in a comprehensive research project in order to provide reliable information on the spatial distribution and control of the mass movements. More than 20% of the scarp slope has been influenced by various types of Holocene mass movements with strong differences in spatial frequencies. Sixteen high-magnitude landslides (Sturzfließungen) were identified by field inspection and mapping of slope geomorphology. Information on locations, morphometric characteristics, stratigraphic positions and rainfall-related attributes of the scarp slopes affected by the large landslides is presented.Mean annual rainfall amounts decrease from more than 800 mm in the western part of the basin to less than 550 mm in the east. Meteorological statistics on the spatial distribution of heavy rainfall intensities of different durations and return periods show that greatest precipitation intensities in short events (1 h) are reached at the western margin. Differences in rainfall intensities between the western and eastern parts decrease with increasing duration of the events. Where available, event-related meteorological information was collected. The spatial distribution of the landslides is most closely mirrored in the pattern of mean annual precipitation, though this variable is generally not thought to be a satisfactory or reliable climatic controlling factor. No landslides occur below a threshold value of 700 mm. The empirical data show that some general level of average perennial water input into the slope system seems to be of decisive importance for the occurrence of high-magnitude mass movements. Only when the precondition of a more general hydrological disposition is fulfilled, a direct triggering of high-magnitude mass movements by a short-time intensive rainfall period or event can become effective.  相似文献   

The Kumtag 016 L5 strewn field,Xinjiang Province,China          下载免费PDF全文

Xiaojia Zeng  Shijie Li  Ingo Leya  Shijie Wang  Thomas Smith  Yang Li  Peng Wang 《Meteoritics & planetary science》2018,53(6):1113-1130

The Kumtag 016 strewn field was found in the eastern part of the Kumtag desert, Xinjiang Province, China. In this study, 24 recovered meteorites have been characterized by a suite of different analytical techniques to investigate their petrography, mineralogy, bulk trace elements, noble gas isotopic composition, density, and porosity. We attribute to the strewn field 22 L5 chondrites with shock stage S4 and weathering grade W2–W3. Two different meteorites, Kumtag 021, an L4 chondrite and Kumtag 032, an L6 chondrite, were recognized within the strewn field area. Moreover, Kumtag 003, an H5 chondrite, was previously found in the same area. We infer that the Kumtag 016 strewn field most likely consists of at least four distinct meteorite falls. The effects of terrestrial weathering on the studied meteorites involve sulfide/metal alteration, chemical changes (Sr, Ba, Pb, and U enrichments and depletion in Cr, Co, Ni, and Cs abundances), and physical modifications (decrease of grain density and porosity). Measurements of the light noble gases indicate that the analyzed Kumtag L5 samples contain solar wind-implanted noble gases with a ²⁰Ne/²²Ne ratio of ~12.345. The cosmic-ray exposure (CRE) ages of the L5 chondrites are in a narrow range (3.6 ± 1.4 Ma to 5.2 ± 0.4 Ma). For L4 chondrite Kumtag 021 and L6 chondrite Kumtag 032, the CRE ages are 5.9 ± 0.4 Ma and 4.7 ± 0.8 Ma, respectively.  相似文献   

A noble gas data collection of lunar meteorites          下载免费PDF全文

Marianna Mészáros  Beda A. Hofmann  Ingo Leya 《Meteoritics & planetary science》2018,53(5):1104-1107

We collected the published noble gas data of altogether 35 lunar meteorites. This compilation includes the stable isotopes of He, Ne, Ar, Kr, and Xe. We also give a summary of cosmogenic, trapped, and radiogenic noble gas components of lunar meteorites for which data are available in the literature.  相似文献   

Phobos-II results and the Martian magnetic field     

Ingo Orgzall  Siegfried Franck 《Earth, Moon, and Planets》1990,48(2):183-186

The results of the Phobos-2 mission concerning the Martian magnetic field are interpreted in the framework of a model for the planetary evolution taking into account certain effects of material properties.  相似文献   

On the influence of noise on measurements with three-dimensional hot-film or hot-wire probes     

Ingo Zank 《Boundary-Layer Meteorology》1980,19(4):487-493

This paper describes the influence of noise on the u, v, and w wind components, which are measured by commonly used rectangular hot-film or hot-wire probes. It is shown that the distortion of the u, v, and w turbulence spectra may be entirely different, even if all three measured cooling velocities are equally disturbed by the same noise signal. A practical formalism is given for estimating the influence of any cooling velocity noise on the spectra and cospectra of u, v, and w. With inverted matrices, the original spectrum of a noise signal in the cooling velocities can be calculated from the observed u, v, and w spectra, assuming that the undisturbed shape of them is known.This work was supported by the Sonderforschungsbereich Meeresforschung of the Deutsche Forschungsgemeinschaft.  相似文献   

Synthesis,properties and stability of end member boromuscovite,KAl<Subscript>2</Subscript>[BSi<Subscript>3</Subscript>O<Subscript>10</Subscript>](OH)<Subscript>2</Subscript>     

Ingo Jung  Werner Schreyer 《Contributions to Mineralogy and Petrology》2003,144(4):507-507

  相似文献