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1.
Summary. Using nine IDA records for the Indonesian earthquake of 1977 August 19, we have formed an optimal linear combination of the records and have measured the frequency and Q of 0 S 0 and 1 S 0. The frequency was measured using the moment ratio method. The attenuation was measured by the minimum width method and by the time-lapse method. The frequency and attenuation were measured simultaneously by varying them to obtain a best fit to the data. A 2000-hr stack, the sum of nine individual records, for 0 S 0 gave a frequency of 0.814664 mHz±4 ppm. The values for the Q of 0 S 0 for the three different methods of measurement were 5600,5833 and 5700, respectively. The error in the estimates of Q -1 is about 5 per cent for the minimum power method. For 1 S 0 a 300-hr stack yielded a frequency of 1.63151 mHz±30 ppm. The values of Q for this mode were 1960, 1800 and 1850, respectively, with an error in Q -1 of about 12 per cent for the minimum power method.  相似文献   
2.
AOX‐formation by the Sonochemical Treatment of Salicylic Acid in Presence of Chloride Ultrasound shows great potential for improving water, wastewater and sludge treatment processes. However, a number of questions exist: for example the influence of suspended solids or salts. In this paper the influence of chloride in view of AOX‐formation should be investigated. As organic model compound salicylic acid (0.05…1 mmol/L) was used. Formation of AOX (adsorbable organically bound halogens) was measured in dependence upon chloride concentrations (1.4…141 mmol/L) and pH 2 and 9. Ultrasound irradiation was performed in glass reactor (500 mL) at 206 kHz and 353 kHz by continuous bubbling argon:oxgen (4:1) at a flow rate of 1 L/min into the solutions. The elimination of salicylic acid and the formation of hydrogen peroxide were not influenced by the presence of chloride (up to 56 mmol/L). The rate of salicylic acid elimination and the formation rate of hydrogen peroxide are at concentrations of mmol/(L min) levels but those of AOX formation of μmol/(L min) levels. The reactions leading to chlorinated by‐products can be seen as minor reaction paths. The yield of AOX depending on frequency, pH and chloride concentration lies between 10 μg/L and 900 μg/L. In acidic medium they were twice as high as in basic medium. Below the ratio chloride : salicylic acid of 2 mol/mol, AOX could not be identified.  相似文献   
3.
ABSTRACT

Classification of floods is often based on return periods of their peaks estimated from probability distributions and hence depends on assumptions. The choice of an appropriate distribution function and parameter estimation are often connected with high uncertainties. In addition, limited length of data series and the stochastic characteristic of the occurrence of extreme events add further uncertainty. Here, a distribution-free classification approach is proposed based on statistical moments. By using robust estimators the sampling effects are reduced and time series of different lengths can be analysed together. With a developed optimization procedure, locally and regionally consistent flood categories can be defined. In application, it is shown that the resulting flood categories can be used to assess the spatial extent of extreme floods and their coincidences. Moreover, groups of gauges, where simultaneous events belong to the same classes, are indicators for homogeneous groups of gauges in regionalization.  相似文献   
4.
A high resolution analysis of benthic foraminifera as well as of aeolian terrigenous proxies extracted from a 37 m-long marine core located off the Mauritanian margin spanning the last ~ 1.2 Ma, documents the possible link between major continental environmental changes with a shift in the isotopic signature of deep waters around 1.0–0.9 Ma, within the so-called Mid-Pleistocene Transition (MPT) time period. The increase in the oxygen isotopic composition of deep waters, as seen through the benthic foraminifera δ18O values, is consistent with the growth of larger ice sheets known to have occurred during this transition. Deep-water mass δ13C changes, also estimated from benthic foraminifera, show a strong depletion for the same time interval. This drastic change in δ13C values is concomitant with a worldwide 0.3‰ decrease observed in the major deep oceanic waters for the MPT time period. The phase relationship between aeolian terrigeneous signal increase and this δ13C decrease in our record, as well as in other paleorecords, supports the hypothesis of a global aridification amongst others processes to explain the deep-water masses isotopic signature changes during the MPT. In any case, the isotopic shifts imply major changes in the end-member δ18O and δ13C values of deep waters.  相似文献   
5.
Gamma-ray burst analyses at neutrino telescopes are typically based on diffuse or stacked (i.e., aggregated) neutrino fluxes, because the number of events expected from a single burst is small. The interpretation of aggregated flux limits implies new systematics not present for a single burst, such as by the integration over parameter distributions (diffuse fluxes), or by the low statistics in small burst samples (stacked fluxes). We simulate parameter distributions with a Monte Carlo method computing the spectra burst by burst, as compared to a conventional Monte Carlo integration. With this approach, we can predict the behavior of the flux in the diffuse limit as well as in low statistics stacking samples, such as used in recent IceCube data analyses. We also include the flavor composition at the detector (ratio between muon tracks and cascades) into our considerations. We demonstrate that the spectral features, such as a characteristic multi-peak structure coming from photohadronic interactions, flavor mixing, and magnetic field effects, are typically present even in diffuse neutrino fluxes if only the redshift distribution of the sources is considered, with z ? 1 dominating the neutrino flux. On the other hand, we show that variations of the Lorentz boost can only be interpreted in a model-dependent way, and can be used as a model discriminator. For example, we illustrate that the observation of spectral features in aggregated fluxes will disfavor the commonly used assumption that bursts with small Lorentz factors dominate the neutrino flux, whereas it will be consistent with the hypothesis that the bursts have similar properties in the comoving frame.  相似文献   
6.
7.
The diet of three Antarctic copepods, Calanus simillimus , Rhincalanus gigas and Pleuromamma robusta , was studied from samples collected during the European iron fertilization experiment (EIFEX) in austral fall 2004. The diet was investigated using microscopical gut content analysis. The food spectra of the three copepod species showed a clear overlap. The pennate diatom Fragilariopsis kerguelensis was commonly found in all guts. Large numbers of cells were fractured, but some were found complete when arranged as chains. The same was true for the genus Chaetoceros , a centric diatom, of which even their long and complete setae could be observed. In general the ingested food particles extended over a wide size range up to a few 100 μm. The copepod C. simillimus , for example, fed on large foraminifera and swallowed them whole. Compared to C. simillimus and R. gigas , P. robusta guts contained a higher percentage and larger diversity of hard-shelled protozoa including tintinnids, Radiolaria and Acantharia.  相似文献   
8.
9.
Production and consumption activities in industrialized countries are increasingly dependent on material and energy resources from other world regions and imply significant economic and environmental consequences in other regions around the world. The substitution of domestic material extraction and processing through imports is also shifting environmental burden abroad and thus extends the responsibility for environmental impacts as well as social consequences from the national to the global level. Based on the results of the Global Resource Accounting Model, this paper presents the first trade balances and consumption indicators for embodied materials in a time series from 1995 to 2005. The model includes 53 countries and two world regions. It is based on the 2009 edition of the input–output tables and bilateral trade data published by the Organisation for Economic Co-operation and Development (OECD) and is extended by physical data on global material extraction. The results quantify the global shift of embodied material resources from developing and emerging countries to the industrialized world. In addition to the level of industrialization and wealth, population density is identified as an important factor for the formation of physical trade patterns. Exports of embodied materials of less densely populated countries tend to surpass their imports, and vice versa. We also provide a quantitative comparison between conventionally applied indicators on material consumption based on direct material flows and indicators including embodied material flows. We show that the difference between those two indicators can be as much as 200%, calling for an adjustment of conventional national material flow indicators. Multi-regional input–output models prove to be a useful methodological approach to derive globally consistent and comprehensive data on material embodiments of trade and consumption.  相似文献   
10.
ABSTRACT

The optimization and extension of existing gauging networks are a challenging task, which can be done under consideration of many different aspects. One possibility is to maximize the obtained information on regional hydrological characteristics by new gauges compared to existing ones. For this, information theory approaches are most suitable. Here, the principle of maximum entropy is applied to calculate the probability of non-similarity of catchments to determine locations of new gauges according to the catchment characteristics that are most relevant for the hydrological conditions. The realization in an interactive application, provided online, makes use easy for practitioners and scientists. Goodness-of-fit measures are applied to investigate the explanatory power of the model and the contribution of each characteristic to the model, which gives information on the most influential properties of the catchment. The relevance of the proposed approach is proven by comparing hydrological signatures between similar and non-similar catchment.  相似文献   
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