2003年新疆石河子5.4级地震前地震活动异常分析

分析了2003年2月14日石河子5．4级地震前北天山地震活动图像和地震学参数异常过程。5．4级地震发生在2002年北天山4级地震集中活动区空段，震前12项地震学参数时间进程存在中、短期异常，3项地震波参数出现短期异常。震前3个月乌鲁木齐震情窗出现超警戒线异常。震前10天震中附近地区地震和震群活动显著。     

Influence of IHSS Standard and Reference Materials on Copper and Mercury Toxicity to Vibrio fischeri

The reduction in light emission of the marine bacterium Vibrio fischeri used in the standard Microtox^® bioassay was measured for the metals copper and mercury. The concentration at which the light emission was reduced by 50% (EC₅₀) was determined to be (3.43 ± 0.83) μmol/L for Cu²⁺ and (0.66 ± 0.01) μmol/L for Hg²⁺. The reduction of the toxicity of these metals by humic and fulvic acids were studied using IHSS Standard and Reference Materials. Copper toxicity was reduced 17...20% by the soil and peat fulvic acids and 9...20% by the aquatic fulvic acids. While there appeared to be little difference in the reduction of Cu toxicity by fulvic acids from soils, peats, or aquatic systems, Hg toxicity was reduced 3.6...7.3% by the soils and peats, while aquatic fulvic acids reduced Hg toxicity 14...16%. Soil fulvic acids appear to have significantly less capacity to reduce Hg toxicity than Cu toxicity. Humic acids had much higher reductions of Cu toxicity (44...124%) compared to the fulvic acids, with little difference between aquatic and soil or peat humic acids, 44...124% and 67...100%, respectively. However, humic and fulvic acids, regardless of origin, had approximately the same effect on Hg toxicity with 3.5...16% reduction by fulvic acids and 8...20% reduction by humic acids. Unlike the fulvic acids, no clear trend was observed relative to origin of the humic acids. There was no correlation between percent reduction of Cu or Hg toxicity by the organic compounds and copper binding capacity (CuBC), C/N ratio, or carboxyl content of the materials. Examination of natural organic matter (NOM) isolated by reverse osmosis techniques from three water sources had reductions of both Cu and Hg toxicity that were most similar to the Suwannee River and Nordic fulvic acids.     

Die neue EG‐Wasserrahmenrichtlinie: Bewertung der chemischen und ökologischen Qualität von Oberflächengewässern

The New EC Framework Water Directive: Assessment of the Chemical and Ecological Status of Surface Waters The main objective of the draft EC Framework Water Directive is the good quality of all surface waters. The directive provides for an assessment of the chemical status of surface waters (EU‐wide valid environmental quality standards for approximately 30 priority substances) and a five‐stage ecological classification of waters, comprising the stages high, good, moderate, poor, and bad. The starting point for the assessment are the reference conditions, which are defined as corresponding to high water quality and characterising a water status with no significant anthropogenic impact. The reference sites in the various water body types are to be selected using hydromorphological and physico‐chemical parameters and subsequently characterised by means of biological parameters. For surface waters, three groups of characteristics are provided for, namely: 1. with priority the biology – in the case of surface waters – with the four elements phytoplankton, macrophytes/phytobenthos, benthic invertebrate fauna, and fish fauna; 2. supporting the hydromorphology, e.g. flowing waters with the three elements hydrological regime, river continuity, and morphological conditions and 3. supporting the physico‐chemical conditions with the three elements general conditions, specific synthetic pollutants, and specific non synthetic pollutants (other than the priority substances of the chemical status).     

Characterization of Estuarine and Fluvial Dissolved Organic Matter by Thermochemolysis using Tetramethylammonium Hydroxide

Selected samples of dissolved organic matter (DOM) isolated by ultrafiltration (UDOM) have been analyzed by thermochemolysis in the presence of tetramethylammonium hydroxide (TMAH). This technique cleaves ester and ether bonds of bio‐ and geological macromolecules and releases monomer subunits and methylates them in situ as their methyl ethers and methyl esters. Compared with conventional pyrolysis, TMAH thermochemolysis avoids decarboxylation of preexisting carboxylic moieties and produces aromatic acids as their methyl esters. Various phenolic derivatives, which might originate from incorporated lignin‐derived structures, from the highly aliphatic and resistant biopolymer cutan and also from proteinaceous materials, were identified among the products produced from UDOM upon thermochemolysis. The presence of lignin derivatives in UDOM indicates input of organic matter derived from terrestrial sources. Various aromatic acids, perhaps representing the final steps in the oxidation of the side‐chain during microbial oxidation of lignin, were released upon TMAH thermochemolysis, suggesting they are structural constituents of the UDOM. Different ratios of lignin‐derived materials, commonly determined using the CuO oxidation method, such as the Δ value, indicative of the amount of lignin present, the acid/aldehyde ratio (Ad/Al)_G, indicative of the extent of oxidative degradation of the lignin component, and the syringyl/guaiacyl (S/G) and p‐hydroxyphenyl/guaiacyl (P/G) ratios, indicative of the contribution for the different types of lignin, were determined.     

Selective Solid Phase Extraction for Separation and Preconcentration of Palladium from Gold Ore and Anode Slime after Complexation with a N4O2 Mixed Donor Ligand Derivative

A selective and sensitive method for the preconcentration, separation, and determination of palladium with flame atomic absorption spectrometry using 4,15‐bis[(4‐methylphenyl)sulfonyl]‐20,21‐dinitro‐2,3,4,5,6,7,9,10,12,13,14,15,16,17‐tetradecahydro‐8,11‐ethano‐1,18,4,8,11,15‐benzodioxa tetraaza cycloicosine (TNACIN) on XAD‐2010 was developed. TNACIN–Pd(II) complex formed acidic aqueous solution (0.075–0.100 M HNO₃) was accumulated on XAD‐2010 and then eluted with 1 M HCl in acetone. The effects of some analytical parameters including pH, TNACIN amount, sample volume, eluent type, and concentration, sample flow rate and matrix ions were studied for optimization of the method. Detection limit and precision were calculated for Pd(II). This method was also verified with CRM and internal standard, and satisfactory results were obtained.     

Stable isotopic signatures of the modern land snail Eremina desertorum from a low-latitude (hot) dry desert—A study from the Petrified Forest,New Cairo,Egypt

This study was conducted on recent desert samples—including (1) soils, (2) plants, (3) the shell, and (4) organic matter from modern specimens of the land snail Eremina desertorum—which were collected at several altitudes (316–360 m above sea level) from a site in the New Cairo Petrified Forest. The soils and shell_{E. desertorum} were analyzed for carbonate composition and isotopic composition (δ¹⁸O, δ¹³C). The plants and organic matter_{E. desertorum} were analyzed for organic carbon content and δ¹³C. The soil carbonate, consisting of calcite plus minor dolomite, has δ¹⁸O values from −3.19 to −1.78‰ and δ¹³C values −1.79 to −0.27‰; covariance between the two values accords with arid climatic conditions. The local plants include C3 and C4 types, with the latter being dominant. Each type has distinctive bulk organic carbon δ¹³C values: −26.51 to −25.36‰ for C3-type, and −13.74 to −12.43‰ for C4-type plants.The carbonate of the shell_{E. desertorum} is composed of aragonite plus minor calcite, with relatively homogenous isotopic compositions (δ¹⁸O_mean = −0.28 ± 0.22‰; δ¹³C_mean = −4.46 ± 0.58‰). Most of the δ¹⁸O values (based on a model for oxygen isotope fractionation in an aragonite-water system) are consistent with evaporated water signatures. The organic matter_{E. desertorum} varies only slightly in bulk organic carbon δ¹³C values (−21.78 ± 1.20‰) and these values suggest that the snail consumed more of C3-type than C4-type plants. The overall offset in δ¹³C values (−17.32‰) observed between shell_{E. desertorum} carbonate and organic matter_{E. desertorum} exceeds the value expected for vegetation input, and implies that 30% of carbon in the shell_{E. desertorum} carbonate comes from the consumption of limestone material.     

Kurzzeit-Toxizitätstests zur Messung der Toxizität von Chemikalien gegenüber Belebtschlamm

Short-term Toxicity Tests for the Measurement of Toxicity of Chemicals Towards Activated Sludge. To avoid severe damage to the activated sludge of a wastewater treatment plant it is necessary to control the sludge activity by means of biological test systems. Especially the short-term respiration assay and the dehydrogenase assay with resazurin as a redox-dye seem to be appropriate for this monitoring program. The practical performance of both test systems was optimized in some essential points. With the help of several reference substances both monitoring systems were tested for practical use as short-term toxicity tests. The results of the investigations showed that the inhibitory concentrations measured in both test systems were partially very different. In monitoring experiments with laboratory-scale wastewater treatment plants it could be shown that a positive correlation between respiration activity and dehydrogenase activity is not always given. Furthermore, a pH-dependent toxicity could be demonstrated for several substituted phenols.     

High-resolution climate variability of southwest China during 57-70 ka reflected in a stalagmite δ18O record from Xinya Cave

A 26-cm-long stalagmite (XY2) from Xinya Cave in northeastern Chongqing of China has been ICP-MS ²³⁰Th/U dated, showing a depositional hiatus at 2.3 cm depth from the top. The growth of the 2.3–26 cm interval determined by four dates was between 57 ka and 70 ka, with a linear growth rate of 0.023 mm/a. We have analyzed 190 samples for δ ¹⁸O and δ ¹³C, mostly in the 2.3–26 cm part. The δ ¹⁸O and δ ¹³C values between 57 ka and 70 ka reveal decadal-to-centennial climatic variability during the glacial interval of Marine Isotope Stage 4 (MIS4), exhibiting much higher resolution than that of the published Hulu and Dongge records during this interval. Speleothem δ ¹⁸O in eastern China, including our study area can be used as a proxy of summer monsoon strength, with lighter values pointing to stronger summer monsoon and higher precipitation, and vice versa. Two decreases in the δ ¹⁸O signature of XY2 record around 59.5 and 64.5 Ka are argued to correspond to the Dansgaard-Oeschger (D-O) events 17 and 18 respectively. The Heinrich event 6 (H6) can be identified in the record as a heavy δ ¹⁸O peak around 60 ka, indicating significant weakening of the monsoon in Chongqing during the cold period. The XY2 δ ¹⁸O record shows very rapid change toward to the interstadial condition of the D-O event, but more gradual change toward to the cold stadial condition. This phenomenon found in the Greenland ice core records is rarely observed so clearly in previously published speleothem records. According to SPECMAP δ ¹⁸O record, the glacial maximum of MIS 4 was around 64.5 ka with the boundary of MIS 3/4 around 60 ka. Unlike the marine record, the speleothem record of XY2, China, exhibits much high frequency variations without an apparent glacial maximum during MIS 4. However, the timing of MIS 3/4 boundary seems to be around 60 ka when the H6 terminated, in agreement with the marine chronology. The growth period of sample XY2 during glacial times probably reflects a local karstic routing of water, rather than having climatic significance. Supported by the National Natural Science Foundation of China (Grant Nos. 40672165, 90511004, 40672202) and the Academician Special Project of Chongqing Science Committee (Grant No. 2003-7835)     

Numerical experiments for Typhoon Dan incorporating AMSU-A retrieved data with 3DVM

Two sets of assimilation experiments on a landfalling typhoon—Typhoon Dan(1999)over the western North Pacific were designed to compare the performances of two kinds of variational data assimilation schemes that are the 3-Dimensional Variational data assimilation of Mapped observation(3DVM)and the 4-dimensional variational data assimilation(4DVar).Results show that:(1)both the 3DVM and 4DVar successfully improved the simulations of typhoon intensity and track incorporating the satellite AMSU-A retrieved temperature and wind data into the initial conditions,and the 3DVM more significantly due to the flow-dependent of background error covariance matrix and observation error covariance matrix like 3-dimensional variational data assimilation(3DVar)circle;(2)inclusions of extra model integration iterations at each observation time in the 3DVM make it more consistent with prediction model;(3)the 3DVM is much more time-saving due to the exclusion of the adjoint technique in it.     

平流层准两年周期振荡对CH4双峰的影响

分析了1992～2001年1月HALOE(卤素掩星试验装置)的CH4资料,研究了CH4的多年平均分布,结果表明:CH4混合比在平流层下层较大,向上迅速减小.同时,中纬度与热带CH4混合比的等压面梯度也随着高度逐渐减小,甚至在平流层顶附近和平流层上层形成双峰,这在北半球的春夏季特别明显.作者用NCAR的SOCRTAES二维模式的模拟结果来分析CH4混合比在平流层顶和平流层上层形成双峰的机理.模式作了以下两个模拟,其一为没有热带纬向风场QBO(准两年振荡)的状况,其二为加入QBO强迫后的模拟.结果发现QBO引起的余差环流对CH4混合比在热带和副热带平流层顶和平流层上层的输送是影响CH4双峰的一个主要原因.