河南省飞机人工增雨试验效果检验

采用区域对比的试验方法，选取1991年至1998年春、秋季试验作业区和对比区内测站逐时历史降水资料，对历史增雨作业效果进行了评估。统计检验结果表明，河南省1991年至1998年春、秋季人工增雨效果分别为20．05％、13．22％，总平均效果为16．63％。     

Reliable radiocarbon dating of fossil pollen grains: It is truly possible

Radiocarbon dating of fossil pollen concentrates has the potential to reduce limitations for sample selection in chronological studies of sedimentary archives. The recent development of the technology for rapidly preparing highly purified fossil pollen concentrates using a cell sorter makes it realistic to turn this dream into reality. Before utilizing pollen as a material for dating with confidence, however, it is necessary to understand the factors that may affect the result of the measurements, and to establish criteria to assess the reliability of the radiocarbon ages produced. In this study, peat soils which are commercially available in large quantities, and are hence used as our laboratory standard, as well as the varved lacustrine sediments from Lake Suigetsu, which has one of the best terrestrial radiocarbon stratigraphies in the world, were used to assess the accuracy of radiocarbon ages of pollen concentrates and to establish an appropriate protocol for sample preparation. A pollen-rich fraction prepared by a recently proposed combined method of physio-chemical pre-treatment and cell sorter (Yamada et al. 2021) was submitted to a range of different posterior treatments and radiocarbon measurement. The results were also compared with SEM (Scanning Electron Microscoic) and Fourier Transform Infrared Spectroscopic observations. It was discovered that the sample prepared by the initial pre-treatment and cell sorter were not sufficiently pure and did not yield radiocarbon ages that were consistent with the terrestrial leaf fossils. Instead, the Acid-Base-Acid treatment with ultrafiltration following on from the cell sorter step proved to be highly effective in the removal of contaminants and improve the measured ages. The comparison with Suigetsu's terrestrial radiocarbon dataset also indicated that accuracy could be improved through closer assessment using the pollen taxa composition, carbon content (%C), and stable isotope ratios (δ¹³C) of the pollen concentrates. The age-depth models established by the radiocarbon dating of fossil pollen grains extracted from the Suigetsu sediments agree very well with that of plant macrofossils, and even improve the precision of the combined model. As long as handling was appropriate, the pollen concentrates prepared by the cell sorter provide reliable radiocarbon ages and the method can significantly contribute to Quaternary sciences in the future.     

Experimental constraints on pre-eruptive water contents and changing magma storage prior to explosive eruptions of Mount St Helens volcano

Compositionally diverse dacitic magmas have erupted from Mount St Helens over the last 4000 years. Phase assemblages and their compositions in these dacites provide information about the composition of the pre-eruptive melt, the phases in equilibrium with that melt and the magmatic temperature. From this information pre-eruptive pressures and water fugacities of many of the dacites have been inferred. This was done by conducting hydrothermal experiments at 850°C and a range of pressures and water fugacities and combining the results with those from experiments at temperatures of 780 and 920°C, to cover the likely range in equilibration conditions of the dacites. Natural phase assemblages and compositions were compared with the experimental results to infer the most likely conditions for the magmas prior to eruption. Water contents disolved in the melts of the dacites were then estimated from the inferred conditions. Water contents in the dacites have varied greatly, from 3.7 to 6.5 wt.%, in the last 4000 years. Between 4000 and about 3000 years ago the dacites tended to be water saturated and contained 5.5 to 6.5 wt.% water. Since then, however, the dacites have been significantly water-undersaturated and contained less than 5.0 wt.% water. These dacites have tended to be hotter and more mafic, and andesitic and basaltic magmas have erupted. These changes can be explained by variable amounts of mixing between felsic dacite and basalt, to produce hotter, drier and more mafic dacites and andesites. The magma storage region of the dacitic magmas has also varied significantly during the 4000 years, with shifts to shallower levels in the crust occurring within very short time periods, possibly even two years. These shifts may be related to fracturing of overlying roof rock as a result of magma with-drawal during larger volume eruptions.     

地震应急基础数据库建设

地震应急数据库建设是地震应急工作的核心环节和主要工作内容,中国的地震应急数据库无论从数据内容上,还是数据库建设涉及面都超过以往任何时候地震系统的数据库建设工作,是近期地震系统面临的主要任务之一。从地震应急基础数据库建设的意义、数据库定义、基本数据内容、数据库的作用、建库方法与原则等多方面对目前正在开展的地震应急基础数据库建设进行了阐述,是对前一阶段地震应急数据库建设工作的一个阶段性总结。     

Sample preparation methods for quantitative detection of DNA by molecular assays and marine biosensors

The need for quantitative molecular methods is growing in environmental, food, and medical fields but is hindered by low and variable DNA extraction and by co-extraction of PCR inhibitors. DNA extracts from Enterococcus faecium, seawater, and seawater spiked with E. faecium and Vibrio parahaemolyticus were tested by qPCR for target recovery and inhibition. Conventional and novel methods were tested, including Synchronous Coefficient of Drag Alteration (SCODA) and lysis and purification systems used on an automated genetic sensor (the Environmental Sample Processor, ESP). Variable qPCR target recovery and inhibition were measured, significantly affecting target quantification. An aggressive lysis method that utilized chemical, enzymatic, and mechanical disruption enhanced target recovery compared to commercial kit protocols. SCODA purification did not show marked improvement over commercial spin columns. Overall, data suggested a general need to improve sample preparation and to accurately assess and account for DNA recovery and inhibition in qPCR applications.     

Modelling hourly evapotranspiration and soil water content at the grass-covered boundary-layer field site Falkenberg,Germany

Abstract

The study analyses a 2-year period of hourly rates of real evapotranspiration (ETr) derived from eddy covariance measurements and soil water contents at depths from 8 to 90 cm, monitored by time domain reflectometry probes at the grass-covered boundary-layer field site Falkenberg of the Lindenberg Meteorological Observatory – Richard-Aßmann-Observatory, operated by the German Meteorological Service (DWD). The ETr rates and soil water contents were compared with the results of a modelling approach consisting of the Penman-Monteith equation and the soil water balance model Hydrus-1D using a noncompensatory and a compensatory root-water uptake model. After optimization of soil hydraulic parameters by inverse modelling, using measured soil water contents as the objective function, simulated and measured model outputs showed good agreement for soil water contents above 90 cm depth and for ETr rates simulated by our modelling approaches using noncompensatory root-water uptake. The application of a compensatory root-water uptake model led to a decrease in the simulation quality for the total investigation period.

Editor Z.W. Kundzewicz

Citation Wegehenkel, M. and Beyrich, F., 2014. Modelling of hourly evapotranspiration and soil water content at the grass-covered boundary-layer field site Falkenberg, Germany. Hydrological Sciences Journal, 59 (2), 376–394.     

Plastic contamination in the decapod crustacean Nephrops norvegicus (Linnaeus, 1758)

The aim of this study was to determine the extent Nephrops consumes plastics in the Clyde Sea and if this intake occurs through their diet. Plastic contamination was found to be high in Nephrops, 83% of the animals sampled contained plastics (predominately filaments) in their stomachs. Tightly tangled balls of plastic strands were found in 62% of the animals studied but were least prevalent in animals which had recently moulted. No significant difference in plastic load was observed between males and females. Raman spectroscopy indicated that some of the microfilaments identified from gut contents could be sourced to fishing waste. Nephrops fed fish seeded with strands of polypropylene rope were found to ingest but not to excrete the strands. The fishery for Norway lobster, Nephrops norvegicus, is the most valuable in Scotland and the high prevalence of plastics in Nephrops may have implications for the health of the stock.     

The Precision Estimate of Multi-Fractal Methods of Time Sequence of Earthquakes

At present,there are many methods of calculating seismic time-fractal.However,there isn’t aquantitative result about the precision of every method.So,in this Paper,we use the digitalimitation of theoretic model to solve precision estimate problems of calculating the precision ofone dimension distribution of theoretic models with Cantor multi-fractal set,we obtained someresults as follows:(1)There exists many problems such as rules,numbers of samples,basicpoint selection,the diffence resulted from different methods and so on.(2)The fixed-massmethod(MAS)and the minimal spanning tree method(MST)can give good structure charac-teristics with different q value,while the counting-boxes method can’t.And the error of thefixed-radius method(RAD)in the range of-q is too big.(3)There are scale problems of rulesfor multi-fractal,it is objective reflection for non-rule area.(4)MST has the boundary prob-lem,while MAS and RAD don’t.(5)With increasing sample number,the precision of allfractal-dimension values becomes     

基于专家知识的神经元网络方法及其在潜在震源区定量划分中的应用

将专家知识和神经元网络方法结合起来，利用专家知识和规则构造规则样本的方法来提高神经元网络学习样本的质量，通过神经元网络对规则样本的学习，形成基于专家知识的神经元网络模型。在潜在震源区划分专家系统中有关规则的基础上，将基于专家知识的神经元网络方法引入到潜在震源区定量划分中，并以首都圈地区为例，对其潜在震源区作了定量划分，结果表明，规则样本能较好的反映专家的知识和规则，利用构造规则样本的方法，可以提高     

THE PROBLEM OF ADEQUATE SAMPLE SIZE IN PATTERN RECOGNITION STUDIES:THE MULTIVARIATE NORMAL CASE

Because many pattern recognition techniques are predicated on the assumption of mutivariate normaldata,Monte Carlo simulation studies were performed to determine the number of samples that arenecessary to describe a multivariate normal population adequately.From these studies we have learnedthat hundreds of sainples are required.These results suggest that parametric procedures should only beused to analyze very large data sets.