GENERALIZED KUNETZ-TYPE EQUATIONS*

A Kunetz equation is often used as the starting point in the development of solutions for the inversion of one-dimensional, noise free, normal incident seismograms, for which |r_o|= 1. In this paper we demonstrate a need for a Kunetz-type equation in which filtered signals can be used, so that noise effects can be reduced. We then show that an infinite number of Kunetz-type equations exist for the lossless wave equation in layered media. Finally, we show that it is indeed valid to formulate and solve the inverse problem using filtered signals.     

Sediment concentrations in run‐off varying with spatial scale in an agricultural subwatershed of the Chinese Loess Plateau

Information is scarce on the spatial‐scale effect on sediment concentrations in run‐off. This study addressed this issue within an agricultural subwatershed of the Chinese Loess Plateau, using data observed at a hilltop plot, three nested hillslope plots, two entire‐slope plots (a combination of hillslope and valley side slope) and the subwatershed outlet. Dominated by the splash and sheet erosions, the hilltop plot has a minimum C_ae (mean sediment concentration for all recorded events) of 45 kg m^?3. Unexpectedly, the high sediment concentrations at the hilltop do not occur at high rainfall intensities or large run‐off events because of the protection of surface soils by relatively thick sheet flows. Because of the emergence of rills, C_ae is as high as 310 kg m^?3 even on the most upper hillslope. Downslope, both C_ae and ESC (extreme large values of recorded sediment concentrations) increase; such a slope length effect attenuates with increasing slope length and event magnitude as a result of insufficient sediment availability associated with rill development. Active mass wastings ensure sufficient sediment supply and thus a spatially invariant C_ae (approximately 700 kg m^?3) and ESC (approximately 1000 kg m^?3) at the scale of the entire slope and subwatershed. Detailed examination shows that most small events experience a decrease in sediment concentrations when moving from the entire slope to the subwatershed, indicating that the spatially invariant sediment concentration is valid only for large run‐off events. This study highlights the control of the spatial scale, which determines the dominant erosional process, on erosional regime. Copyright © 2015 John Wiley & Sons, Ltd.     

Run‐off formation in a humid,temperate headwater catchment using a combined hydrological,hydrochemical and isotopic approach (Jizera Mountains,Czech Republic)

The formation of baseflow and stormflow was examined in the 1.18 km² part of the headwater catchment Uhlí?ská, Jizera Mountains, Czech Republic, over the period 2007–2011, by means of run‐off data and environmental tracers ¹⁸O and SiO₂. The baseflow, computed using the digital filter approach BFLOW, contributes 67% to total streamflow and has a mean residence time of 12.3 months. It is formed by groundwater discharge from the valley deluviofluvial granitic sediments, in combination with soil water in weathered layers on hillslopes during rainfall and snowmelt periods. The prevailing source of the groundwater is the infiltration of snowmelt water. Analysis of 20 run‐off events and their hysteretic patterns demonstrated that the stormflow water has a residence time of about 4 months and is generated by preferential flow on hillslopes combined by soil matrix drainage. Because of slower flow in the soil matrix, the enrichment of pore water in SiO₂ is more pronounced. The stormflow and snowmelt water flowing via preferential pathways of upslope minerals soils pushes the pre‐event groundwater through the pathways in wetlands to the stream, and the wetland can be therefore considered as groundwater supplied. This mechanism has been found to be typical for the groundwater‐supplied headwater catchments of the Jizera Mountains and can be also assumed in other mountainous headwaters of the granitic massif in Central Europe. The main methodological contribution of this study are the residence time calculations stratified by baseflow and event flow, identifying run‐off components of different travel times to streams and linking them with geochemical run‐off sources. This achievement was possible because of a comprehensive dataset on hydrology, stable isotopes and silica hydrochemistry in all relevant run‐off generation components. This concept indicates that a possible long‐term change in snowmelt may affect the run‐off regime of headwater catchments to climate or land‐use changes. Copyright © 2013 John Wiley & Sons, Ltd.     

Spatially distributed long‐term hydrologic simulation using a continuous SCS CN method‐based hybrid hydrologic model

A continuous Soil Conservation Service (SCS) curve number (CN) method that considers time‐varied SCS CN values was developed based on the original SCS CN method with a revised soil moisture accounting approach to estimate run‐off depth for long‐term discontinuous storm events. The method was applied to spatially distributed long‐term hydrologic simulation of rainfall‐run‐off flow with an underlying assumption for its spatial variability using a geographic information systems‐based spatially distributed Clark's unit hydrograph method (Distributed‐Clark; hybrid hydrologic model), which is a simple few parameter run‐off routing method for input of spatiotemporally varied run‐off depth, incorporating conditional unit hydrograph adoption for different run‐off precipitation depth‐based direct run‐off flow convolution. Case studies of spatially distributed long‐term (total of 6 years) hydrologic simulation for four river basins using daily NEXRAD quantitative precipitation estimations demonstrate overall performances of Nash–Sutcliffe efficiency (E_NS) 0.62, coefficient of determination (R²) 0.64, and percent bias 0.33% in direct run‐off and E_NS 0.71, R² 0.72, and percent bias 0.15% in total streamflow for model result comparison against observed streamflow. These results show better fit (improvement in E_NS of 42.0% and R² of 33.3% for total streamflow) than the same model using spatially averaged gauged rainfall. Incorporation of logic for conditional initial abstraction in a continuous SCS CN method, which can accommodate initial run‐off loss amounts based on previous rainfall, slightly enhances model simulation performance; both E_NS and R² increased by 1.4% for total streamflow in a 4‐year calibration period. A continuous SCS CN method‐based hybrid hydrologic model presented in this study is, therefore, potentially significant to improved implementation of long‐term hydrologic applications for spatially distributed rainfall‐run‐off generation and routing, as a relatively simple hydrologic modelling approach for the use of more reliable gridded types of quantitative precipitation estimations.     

Hydrostatic theory of the Earth and its mechanical implications

A second-order hydrostatic theory is developed on the assumption that the trace of the Earth's inertia tensor, its mass and mean radius are invariant under any process causing deviations from the hydrostatic state.The hydrostatic flattening and the zonal coefficients of the hydrostatic gravitational field are obtained as ?^?1 = 299.638, J₂ = 1072.618 × 10^?6 and J₄ = ?2.992 × 10^?6, respectively.The internal theory using the preliminary reference earth model (PREM) of Dziewonski and Anderson (1981) yields ?^?1 = 299.627, J₂ = 1072.701 × 10^?6 and J₄ = ?2.992 × 10^?6. The agreement between these and the hydrostatic values indicate that PREM is suitable as a reference model as it represents the spheroidal density distribution in a state of zero non-hydrostatic stress while satisfying the fundamental geodetic observations of the invariant quantities.The small discrepancy between the hydrostatic flattening and the value deduced from PREM suggests that the density is underestimated at large depths and/or it is slightly overestimated in shallow regions of the Earth.The discrepancies between the hydrostatic and observed quantities persist after the removal of the accountable effects of isostatically compensated topography, permanent tidal deformation and the present mass anomalies associated with the Late-Pleistocene deglaciation. These ‘corrected’ discrepancies point to a triaxial non-hydrostatic figure which cannot be explained by the delayed response of the Earth to tidal deceleration.     

Long-term plankton studies at the lower Rhine/Germany

The river Rhine has lain under considerable anthropogenic stress of its water quality for 100 years. As early as 1905 the first results of studies of the plankton in the Rhine were published. Due to the long residence time of the water a real potamoplankton can develop and at the end of the Lower Rhine it reaches its highest density. The paper consists of two parts. At first an overview is given about the history of plankton studies in the Rhine. The second part is the presentation of results from a monitoring at the Lower Rhine from 1979 to 2004.First systematic studies started at the beginning of the 20th century at the beginning of pollution. Our studies started during a phase of recreation from extreme pollution and eutrophication. Samples were taken at four stations: Bad Honnef, km 640, entrance to North Rhine-Westphalia, Düsseldorf, km 732, Duisburg, km 792 downstream large industrial effluents and big cities, Kleve-Bimmen, km 865 at the border to the Netherlands.In the 1970s nutrients were high, especially phosphate 0.65 mg PO₄-P L⁻¹ in 1979. After 1980 phosphate dropped to 0.11 mg PO₄-P L⁻¹ in 2004 (mean values of the growing season). Ammonia was reduced from about 0.52 (1979) to 0.02 (2004) mg NH₄-N L⁻¹. Nitrate remained between 3.72 (1989) and 2.26 (2004) mg NO₃-N L⁻¹ at a relatively high level. Oxygen concentrations were very low during the 1960s and 1970s, sometimes only 4 mg L⁻¹ O₂. During our studies the oxygen increased up to 9 mg L⁻¹ O₂ with a tendency to 11 mg L⁻¹ O₂ in the last years. Chlorophyll a was estimated to be between 59 (1979) and 31μg L⁻¹ (1986) with short peaks up to 170 μg L⁻¹ (1989). Since 1992 the mean values have varied between 30 (1993) and 21 μg L⁻¹ (2004).The floristic phytoplankton composition is characterised by the dominance of the centric diatom Stephanodiscus hantzschii. Other diatoms like Skeletonema subsalsum, Skeletonema potamos and Asterionella formosa were regularly present in smaller quantities. The second dominant group was coccale green algae. During the 1980s they formed up to 35% of the biomass. Since the 1990s their contribution to the phytoplankton became much smaller. This change corresponds with the increase of wastewater treatment and the diminution of nutrients. All the other groups of algae were present in minor quantities. During the time of higher trophy in the 1970s and 1980s the phytoplankton formed two peaks, in recent years only one peak has developed, depending on different flow conditions during the growing season and lower trophic state in the upstream parts of the river.Excellent correspondence exists between cell number, biovolume and chlorophyll a content and the results of delayed fluorescence (DF) measurement. The trophic status in the Lower Rhine may be estimated as (moderate) eutrophic. The ecological status of the phytoplankton is good based on the requirements of the European Water Framework Directive (WFD).The zooplankton consists mainly of rotatoria and larvs of Dreissena polymorpha. Grazing on phytoplankton seems to be mainly due to the large quantities of benthic Dreissena and the newly introduced mussel Corbicula.     

Organic matter,sediment particle size and nutrient distributions in a sewage affected shallow channel

Sediment and seawater samples were taken in a sewage affected channel in Blanca Bay, Argentina. Protein content, ‘humic substances’ and silt-clay percentage were evaluated in the sediments; NH₄⁺, PO₄^3? and ‘dissolved organic matter’ in seawater. A highly significant correlation (r=0.747, n=59) was obtained for the relation between protein and % silt-clay. The ‘humic substances’ distribution depends more on the distance from the outfall than does the protein content, probably because of the important relation of the latter with the sediment particle size. The dissolved components showed a dilution pattern similar to that of a contaminant plume in a moving water mass, reaching normal values at 1700 m from the outfall.     

Assessing DOC export from a Sphagnum‐dominated peatland using δ13C and δ18O–H2O stable isotopes

Dissolved organic carbon (DOC) originating in peatlands can be mineralized to carbon dioxide (CO₂) and methane (CH₄), two potent greenhouse gases. Knowledge of the dynamics of DOC export via run‐off is needed for a more robust quantification of C cycling in peatland ecosystems, a prerequisite for realistic predictions of future climate change. We studied dispersion pathways of DOC in a mountain‐top peat bog in the Czech Republic (Central Europe), using a dual isotope approach. Although δ¹³C_DOC values made it possible to link exported DOC with its within‐bog source, δ¹⁸O_H2O values of precipitation and run‐off helped to understand run‐off generation. Our 2‐year DOC–H₂O isotope monitoring was complemented by a laboratory peat incubation study generating an experimental time series of δ¹³C_DOC values. DOC concentrations in run‐off during high‐flow periods were 20–30 mg L^?1. The top 2 cm of the peat profile, composed of decaying green moss, contained isotopically lighter C than deeper peat, and this isotopically light C was present in run‐off in high‐flow periods. In contrast, baseflow contained only 2–10 mg DOC L^?1, and its more variable C isotope composition intermittently fingerprinted deeper peat. DOC in run‐off occasionally contained isotopically extremely light C whose source in solid peat substrate was not identified. Pre‐event water made up on average 60% of the water run‐off flux, whereas direct precipitation contributed 40%. Run‐off response to precipitation was relatively fast. A highly leached horizon was identified in shallow catotelm. This peat layer was likely affected by a lateral influx of precipitation. Within 36 days of laboratory incubation, isotopically heavy DOC that had been initially released from the peat was replaced by isotopically lighter DOC, whose δ¹³C values converged to the solid substrate and natural run‐off. We suggest that δ¹³C systematics can be useful in identification of vertically stratified within‐bog DOC sources for peatland run‐off.     

Cosmoradiogenic ghosts and the origin of Ca-Al-rich inclusions

The Ca-Al-rich inclusions within Allende are described as quickly frozen non-equilibrated partial melts arising from energetic collisions between centimeter-sized mechanical accumulations of cold presolar grains. The resulting minerals are refractory-rich because refractory supernova condensates are the most persistent components of the preheated accumulates. The shock heating drives off most of the more volatile matrix that had accumulated cold around the refractory cores, which quickly recrystallize while picking up isotopically homogenized trace elements. This picture is advanced to account for the isotopic anomalies in those elements for which fractionation of stardust from gas also fractionates a special isotope whose stellar condensation history can be expected to have been special.I call the anomaly that would have existed before the special component was added anisotopic ghost. These ghosts can be larger than the special anomaly surviving today in meteorites and planets. I argue that ghosts in²⁶Mg/²⁴Mg,⁸⁷Sr/⁸⁶Sr, and^206,207Pb/²⁰⁴Pb have caused erroneous cosmoradiogenic estimates of large age differences between meteorites, their special phases, and even the Moon.     

The effects of initial soil moisture conditions on swale flow hydrographs

The effects of soil water content (SWC) on the formation of run‐off in grass swales draining into a storm sewer system were studied in two 30‐m test swales with trapezoidal cross sections. Swale 1 was built in a loamy fine‐sand soil, on a slope of 1.5%, and Swale 2 was built in a sandy loam soil, on a slope of 0.7%. In experimental runs, the swales were irrigated with 2 flow rates reproducing run‐off from block rainfalls with intensities approximately corresponding to 2‐month and 3‐year events. Run‐off experiments were conducted for initial SWC (SWC_ini) ranging from 0.18 to 0.43 m³/m³. For low SWC_ini, the run‐off volume was greatly reduced by up to 82%, but at high SWC_ini, the volume reduction was as low as 15%. The relative swale flow volume reductions decreased with increasing SWC_ini and, for the conditions studied, indicated a transition of the dominating swale functions from run‐off dissipation to conveyance. Run‐off flow peaks were reduced proportionally to the flow volume reductions, in the range from 4% to 55%. The swale outflow hydrograph lag times varied from 5 to 15 min, with the high values corresponding to low SWC_ini. Analysis of swale inflow/outflow hydrographs for high SWC_ini allowed estimations of the saturated hydraulic conductivities as 3.27 and 4.84 cm/hr in Swales 1 and 2, respectively. Such estimates differed from averages (N = 9) of double‐ring infiltrometer measurements (9.41 and 1.78 cm/hr). Irregularities in swale bottom slopes created bottom surface depression storage of 0.35 and 0.61 m³ for Swales 1 and 2, respectively, and functioned similarly as check berms contributing to run‐off attenuation. The experimental findings offer implications for drainage swale planning and design: (a) SWC_ini strongly affect swale functioning in run‐off dissipation and conveyance during the early phase of run‐off, which is particularly important for design storms and their antecedent moisture conditions, and (b) concerning the longevity of swale operation, Swale 1 remains fully functional even after almost 60 years of operation, as judged from its attractive appearance, good infiltration rates (3.27 cm/hr), and high flow capacity.     

Mantle-derived volatiles in continental crust: the Massif Central of France

CO₂-rich gases and groundwaters from springs and boreholes originating within the basement of the Massif Central have variable³He/⁴He ratios with correspondingR/R_a values ranging from 0.8 to 5.5 and 0.3 to 2.8 respectively, indicating the presence of a significant component of mantle helium. Molar concentrations of rare gases in the CO₂-rich gases are approximately 5 orders of magnitude greater than in the waters and suggest that a near-surface Henry's Law fractionation has occurred between exsolving CO₂ and water.δ¹³C values of the CO₂-rich gases are in the range −4.2 to −6.1‰, i.e. in that range normally attributed to mantle carbon, but which could also represent an average crustal composition and therefore do not discriminate between mantle and crustal sources.C/³He ratios show 4 orders of magnitude variation from 1.4 × 10¹² to 5 × 10⁸ and, compared to a mantleC/³He ratio of 10⁹, indicate that either a complex fractionation has occurred between mantle helium and mantle CO₂ or more likely that mantle rare gases have been diluted by large quantities of CO₂ with an average crustal carbon isotope composition. The regional distribution of³He and C does not show any obvious relationship to age or proximity of volcanic centres or major faults, suggesting that mantle-derived C and He components decoupled from their silicate melt sources at some depth.The results from this area of active fluid circulation suggest that C-isotope data derived from metamorphic terrains should be interpreted with great caution, but that input of some mantle-derived carbon is expected to accompany crustal extension.     

藏南羊卓雍错湖面大气湍流特征观测分析

湍流运动是大气边界层的本质特征,是地表与大气之间能量和物质交换的主要方式.本文利用2016和2017年4-10月藏南羊卓雍错湖泊涡动观测资料,分析了湖面大气湍流方差和湍流特征量的统计和变化特征.结果表明：（1）不稳定层结下,三维风速分量和超声虚温、水汽密度、CO₂密度的无量纲标准差随稳定度变化符合Monin-Obukhov相似理论的"1/3"或"-1/3"次幂律,垂直风速的拟合效果最好;稳定层结下,除CO₂密度无量纲标准差与稳定度无明显关系外,其他量基本上满足相似性规律;中性条件下,以上物理量的无量纲标准差分别趋近常数：3.57、3.93、0.77、20.91、6.35和11.96.（2）水平方向平均湍流强度（0.60和0.58）大于垂直方向（0.13）,三维方向湍流强度与平均风速的变化呈显著负相关,相关系数分别为-0.39、-0.42和-0.34.（3）湖面湍流动能随风速呈线性增长,增长率达0.45 m/s;近中性层结时湍流动能最大,层结越稳定或不稳定湍流动能均减小.（4）湖泊下午到傍晚动量输送较强,13：00-22：30时间段平均动量通量达0.091 kg/（m·s²）;热量输送以潜热为主,潜热通量日平均值（77.3 W/m²）是感热通量（14.6 W/m²）的5.3倍,感热和潜热通量日变化峰值分别出现在5：30（22.4 W/m²）和16：00（106.6 W/m²）.     

The coagulation of dissolved239, 240Pu in estuaries as determined from a mixing experiment

A mixing experiment, using large volumes (100 l) of filtered (< 1 μm) freshwater and seawater end-members, was performed to simulate and investigate the chemical reactivity of^{239, 240}Pu during estuarine mixing. An organic-rich freshwater with a relatively high concentration (0.8 dpm/100 l) of dissolved^{239, 240}Pu was used as one end-member; Buzzards Bay seawater (dissolved^{239, 240}Pu= 0.04dpm/100l) was the other. The results demonstrate that dissolved^{239, 240}Pu in the freshwater undergoes extensive and rapid coagulation under simulated estuarine conditions. There is a strong correlation between the amount of coagulation of dissolved^{239, 240}Pu, humic acids (HA), and Fe. The extent of coagulation of all three constituents increases with increasing salinity and the net extent of their removal is 53%, 57%, and 100% for Pu, HA, and Fe respectively. As has been documented for Fe in freshwater, dissolved^{239, 240}Pu appears to be stabilized by naturally occurring humic substances to form negatively charged colloids which are then coagulated by seawater cations. The extrapolation of these experimental results to real estuaries will require additional research.     

Laboratory Testing of Sulfamethoxazole and its Metabolite Acetyl‐Sulfamethoxazole in Soil

The fate of ¹⁴C‐labeled sulfamethoxazole and acetyl‐sulfamethoxazole in soil has been investigated with special respect to possible entry routes of human and veterinary pharmaceuticals into soil environments. Therefore, the stability of the test substances was monitored first in sewage sludge and bovine manure. Within the incubation period of 72 d, 1% at maximum of the initially applied radiotracers was released as ¹⁴C‐carbon dioxide while ?75% was transferred to non‐extractable residues that were operationally defined by the ethyl acetate extraction. Test‐sludge and test‐manure samples with defined aged residues were prepared and, supplementary to standard solutions, applied to silty‐clay soil samples. After standard and test‐sludge application, soil/water distribution coefficients of K_d < 5 L kg^–1 were determined revealing both test substances as potential leachers. In contrast, the sorption of sulfamethoxazole increased after test‐manure application (K_d > 10 L kg^–1). In the long‐term degradability tests, the metabolic fate of both test substances was characterized by the continuous decrease of extractable residues, resulting in disappearance times of DT₉₀ ? 33 d, and the increase of non‐extractable residues. Mineralization reached 11% at maximum. Thereby, the dynamics of these processes differed whether the test substances were applied via standard, test‐sludge or test‐manure application. This fact emphasized the relevance of entry route specific matrix effects on the fate of both test substances in soil.     

Measurement of surface water runoff from plots of two different sizes

Intensities and amounts of water infiltration and runoff on sloping land are governed by the rainfall pattern and soil hydraulic conductivity, as well as by the microtopography and soil surface conditions. These components are closely interrelated and occur simultaneously, and their particular contribution may change during a rainfall event, or their effects may vary at different field scales. The scale effect on the process of infiltration/runoff was studied under natural field and rainfall conditions for two plot sizes: small plots of 0·25 m² and large plots of 50 m². The measurements were carried out in the central region of Chile in a piedmont most recently used as natural pastureland. Three blocks, each having one large plot and five small plots, were established. Cumulative rainfall and runoff quantities were sampled every 5 min. Significant variations in runoff responses to rainfall rates were found for the two plot sizes. On average, large plots yielded only 40% of runoff quantities produced on small plots per unit area. This difference between plot sizes was observed even during periods of continuous runoff. Copyright © 2002 John Wiley & Sons, Ltd.     

Convective instabilities in a variable viscosity fluid cooled from above

Whether in the mantle or in magma chambers, convective flows are characterized by large variations of viscosity. We study the influence of the viscosity structure on the development of convective instabilities in a viscous fluid which is cooled from above. The upper and lower boundaries of the fluid are stress-free. A viscosity dependence with depth of the form ν₀ + ν₁ exp(?γ.z) is assumed. After the temperature of the top boundary is lowered, velocity and temperature perturbations are followed numerically until convective breakdown occurs. Viscosity contrasts of up to 10⁷ and Rayleigh numbers of up to 10⁸ are studied.For intermediate viscosity contrasts (around 10³), convective breakdown is characterized by the almost simultaneous appearance of two modes of instability. One involves the whole fluid layer, has a large horizontal wavelength (several times the layer depth) and exhibits plate-like behaviour. The other mode has a much smaller wavelength and develops below a rigid lid. The “whole layer” mode dominates for small viscosity contrasts but is suppressed by viscous dissipation at large viscosity contrasts.For the “rigid lid” mode, we emphasize that it is the form of the viscosity variation which determines the instability. For steep viscosity profiles, convective flow does not penetrate deeply in the viscous region and only weak convection develops. We propose a simple method to define the rigid lid thickness. We are thus able to compute the true depth extent and the effective driving temperature difference of convective flow. Because viscosity contrasts in the convecting region do not exceed 100, simple scaling arguments are sufficient to describe the instability. The critical wavelength is proportional to the thickness of the thermal boundary layer below the rigid lid. Convection occurs when a Rayleigh number defined locally exceeds a critical value of 160–200. Finally, we show that a local Rayleigh number can be computed at any depth in the fluid and that convection develops below depth z_r (the rigid lid thickness) such that this number is maximum.The simple similarity laws are applied to the upper mantle beneath oceans and yield estimates of 5 × 10¹⁵?5 × 10¹⁶ m² s^?1 for viscosity in the thermal boundary layer below the plate.     

Investigations on cosmic-ray-produced nuclides in iron meteorites, 3. Exposure ages,meteoroid sizes and sample depths determined by mass spectrometric analyses of potassium and rare gases

Three physical quantities define the essentials of the cosmic ray exposure history of a sample of an iron meteorite: (1) the cosmic ray exposure age T, (2) the pre-atmospheric “size” S of the irradiated body, and (3) the location, i.e. the “depth” D, of the samples within the body. To establish these quantities for a given sample three independent quantities must be determined experimentally. In the present work T is ascertained by the ⁴¹K/⁴⁰K method and the ⁴He and ²¹Ne concentrations (C₄ and C₂₁) are measured by the isotope dilution method. Signer and Nier's evaluation of the rare gas distribution in the meteorite Grant and the measured exposure age for this meteorite provide the relationships allowing to ascertain for any meteorite the quantities S and D from the ²¹Ne production rate (P₂₁ = C₂₁/T) and the ⁴He/²¹Ne ratio.Earlier measurements have provided data on the isotopic composition of potassium in 74 different iron meteorites. New rare gas measurements are reported for some 40 samples. Results on the age, size and depth are obtained for almost 60 samples. These data suggest that Signer and Nier's model is well suited for describing not only the rare gas distribution in a single selected meteorite (Grant) but also the exposure histories of the great majority of all irons. For a few samples, however, secondary breakups of the meteoroid and a two- or multiple-stage irradiation must be invoked. Further measurements are proposed for testing and, possibly, refining the still somewhat uncertain relationships between the abundances of cosmogenic nuclides and the quantities T, S, and D in very large meteorites.Histograms are presented showing the age distributions for irons of different chemical groups and of different size ranges.The feasibility and the relative merits of other methods for the determination of T, S, and D are discussed.     

Estimating daily inflows of large lakes using a water‐balance‐based runoff coefficient scaling approach

Daily river inflow time series are highly valuable for water resources and water environment management of large lakes. However, the availability of continuous inflow data for large lakes is still relatively limited, especially for large lakes situated within humid plain regions with tens or even hundreds of tributaries. In this study, we choose the fifth largest freshwater Lake Chaohu in China as our study area to introduce a new approach to reconstruct historical daily inflows at ungauged subcatchments of large lakes. This approach makes use of water level, lake surface rainfall, evaporation from the lake, and catchment rainfall observations. Rainfall–runoff relationship at a reference catchment was analysed to select rainfall input and estimate run‐off coefficient firstly, and the run‐off coefficient was then transferred to ungauged subcatchments to initially estimate daily inflows. Run‐off coefficient was scaled to adjust daily inflows at ungauged subcatchments according to water balance of the lake. This approach was evaluated using sparsely measured inflows at eight subcatchments of Lake Chaohu and compared with the commonly used drainage area ratio method. Results suggest that the inflow time series reconstructed from this approach consistent well to corresponding observations, with mean R² and Nash–Sutcliffe efficiency values of 0.69 and 0.6, respectively. This approach outperforms drainage area ratio method in terms of mean R² and Nash–Sutcliffe efficiency values. Accuracy of this approach holds well when the number of water‐level station being used decreased from four to one.     

针铁矿对湖泊草、藻来源可溶有机质的非均质吸附

为探究富营养化湖泊中自生源可溶有机质(DOM)在泥水界面的吸附行为,以马来眼子菜(Potamogeton malaianus)和铜绿微囊藻(Microcystis aeruginosa)释放的DOM为代表,考察针铁矿对草、藻源DOM中不同组分的吸附特征.三维荧光平行因子分析表明类富里酸组分C1和类胡敏酸组分C4的含量很低,而类蛋白物质(类酪氨酸组分C2和类色氨酸组分C3)分别占草、藻源DOM荧光组成的70%和93%. 2种DOM均可被针铁矿吸附,吸附过程符合伪一级动力学.通过等温线拟合发现针铁矿吸附藻源DOM的非线性更强,饱和吸附量(23.77 mg/g)高于草源DOM(19.10 mg/g).特别地,类蛋白组分呈现非线性吸附,而类腐殖物质的吸附近似线性,且针铁矿对于DOM各荧光组分的吸附量顺序为:C3C2 C4 C1,此非均质吸附特征与DOM组分的初始含量、分子大小、芳香性及有效吸附位点有关.红外光谱证实氨基、羧基和羟基是吸附过程中的重要官能团.因此,草、藻源DOM显著改变了针铁矿表面的有机物质组成,影响湖泊沉积物的生物地球化学行为.     

Anwendung von biologischen Testverfahren an Abwässern der Textilindustrie

Testing Effluents of the Textile Refining Industry with Biological Methods The environmental problems caused by the manufacture of finished textiles involve a long chain of individual processes. This “textile chain” includes very diverse enterprises of varied size and structure. The textile refiners occupy a key position in the “textile chain”. On the one hand, this is due to their use of an obscurely large number of chemicals which can end up in the wastewater as well as in the textile products. On the other hand, this key role of the textile refining industry is based on their central position between the preproduction stage and the consumers. This study dealt with the textile refining industry's wastewater. As measured by volume and contents of its wastewater, this industry can be counted among the major industrial plants which discharge into municipal wastewater treatment plants. German wastewater legislation includes the provision that substances which are toxic, persistent, capable of accumulating, carcinogenic, fetotoxic or mutagenic be kept out of natural waters as well as technically possible (Wasserhaushaltsgesetz WHG). Several biotest methods for examining the effect of the substances contained in the wastewater were incorporated into the appendix of the German wastewater regulation (Rahmenabwasser-Verwaltungsvorschrift based on § 7a WHG). The aim of this study was to show, with the aid of biotest methods, how strongly the wastewater of textile refining companies is polluted as compared to other known industrial branches and to what degree the pollution of these wastewaters is eliminated by the treatment in wastewater treatment plants. Finally, we experimented to find out which biotest methods were suited for the examination of these wastewaters. The study's results show that the ecotoxicity of the textile refining industry's wastewater was only extraordinary high in isolated cases as compared to other examined branches of industry. The textile wastewaters exhibit values of G_L = 3 to G_L = 96 in the luminescent bacteria test, G_D = 1 to G_D = 192 (with one exception of G_D > 30000) in the daphnia test and G_F < = 2 to G_F = 32 in the fish test. It turned out though, that a large number of the samples from the textile refining companies (27%) reacted mutagenically in the Ames test in their native state. Consecutive tests for chromosomal aberrations (V79 hamster cell test) also showed mutagenic potential in five out of nine native samples. The employed testing methods with fish, daphnia and luminescent bacteria demonstrate a higher sensitivity of the luminescent bacteria and/or the daphnia as opposed to the fish in most cases. As the fish test is controversial anyway on the grounds of animal protection, a replacement of the fish test by these other tests should be aimed at: on account of the different end points of the luminescent bacteria and the daphnia test, a combination of these tests appears most sensible.