1:25万多目标区域地球化学调查样品的分析测试质量监控方法

在1：25万多目标区域地球化学调查样品分析的质量监控方法中，提出以准确度与精密度并重，标准物质监控与重复样监控相结合。利用“多目标化探样品计算机管理软件”，实现对调查样品分析质量监控的自动化管理。应用该系统软件，只要建立好相应的分析数据库，就可自动获得分析报告、报出率、内检样检查、标样检查、标样监控图等监控数据。     

The A.D. 79 eruption as a future explosive scenario in the Vesuvian area: evaluation of associated risk

 Due to the lack of an effective policy of planning and prevention, over the past decades the area around Mt. Vesuvio has undergone a steady increase in population and uncontrolled housing development. Consequently, it has become one of the most hazardous volcanic areas in the world. In order to mitigate the damage that the impact of an explosive event would cause in the area, the Department of Civil Defense has worked out an Emergency Management Plan using the A.D. 1631 subplinian eruption as the most probable short-term event. However, from 25 000 years B.P. to present, the activity of the Somma-Vesuvio volcano has shown a sequence of eight eruptive cycles, which always began with a strong plinian eruption. In this paper we utilize the A.D. 79 eruption as an example of a potential large explosive eruption that might occur again at Vesuvio. A detailed tephrostratigraphic analysis of the eruption products was processed by a multivariate statistical analysis. This analysis proved useful for identifying marker layers in the sequences, thus allowing the recognition of some major phases of synchronous deposition and hence the definition of the chronological and spatial evolution of the eruption. By combining this reconstruction with land-use maps, a scenario is proposed with time intervals in the eruptive sequence similar to those reported in Pliny's letter. Thus, it was calculated that, after 7 h from the start of the eruption, a total area of approximately 300 km² would be covered with the eruption products. In the following 11 h, a total area of approximately 500 km² would be involved. The third and last phase of deposition would not cause significant variation in the total area involved, but it would bring about an increase in the thickness of the pyroclastic deposits in the perivolcanic area. Received: 30 November 1996 / Accepted: 29 May 1997     

Bromide as a conservative tracer for soil-water studies

The assumption that potassium bromide is a conservative tracer for soil-water studies was tested in a series of batch sorption experiments. Sorption experiments were conducted on soil samples collected from the O, E, and A horizons of the Albemarle soil series near Charlottesville, VA. The experiments were conducted under conditions of differing bromide concentration and filter treatments. Bromide concentrations in soil-solution mixtures were measured through time using an Orion bromide-specific electrode. An analysis of variance of results showed no significant sorption of bromide through time under any concentration level or filter treatment (α = 0·01). No sorption of bromide between different soil horizons could be determined. This work clearly indicates that bromide is conservative under the conditions examined.     

地形作用下有限振幅Rossby波的稳定性分析

本文用微分方程定性理论方法分析了地形对有限振幅Rossby波的稳定性影响。结果表明:地形北坡有利于波动出现不稳定,南坡使波动稳定;西坡使导式波动不稳定但使曳式波动稳定,东坡使导式波动稳定但使曳式波动不稳定。     

区域地理信息系统在农业中的应用——以福建省浦城县为例

本文应用系统分析的理论和方法，建立了浦城县地理信息系统，分析了信息系统的结构、功能及信息管理过程，并在系统的支持下对浦城县农业发展战略进行决策研究，提出了一系列分析意见，开辟了地理信息系统应用的新领域。     

Volcanic risk ranking for Auckland, New Zealand. I: Methodology and hazard investigation

Volcanic eruptions typically produce a number of hazards, and many regions are at risk from more than one volcano or volcanic field. So that detailed risk assessments can be carried out, it is necessary to rank potential volcanic hazards and events in terms of risk. As it is often difficult to make accurate predictions regarding the characteristics of future eruptions, a method for ranking hazards and events has been developed that does not rely on precise values. Risk is calculated individually for each hazard from each source as the product of likelihood, extent and effect, based on the parameters order of magnitude. So that multiple events and outcomes can be considered, risk is further multiplied by the relative probability of the event occurring (probability_e) and the relative importance of the outcome (importance_o). By adding the values obtained, total risk is calculated and a ranking can be carried out.This method was used to rank volcanic hazards and events that may impact the Auckland Region, New Zealand. Auckland is at risk from the Auckland volcanic field, Okataina volcanic centre, Taupo volcano, Tuhua volcano, Tongariro volcanic centre, and Mt. Taranaki volcano. Relative probabilities were determined for each event, with the highest given to Mt. Taranaki. Hazards considered were, for local events: tephra fall, scoria fall and ballistic impacts, lava flow, base surge and associated shock waves, tsunami, volcanic gases and acid rain, earthquakes and ground deformation, mudflows and mudfills, lightning and flooding; and for distal events: tephra fall, pyroclastic flows, poisonous gases and acid rain, mudflows and mudfills, climate variations and earthquakes. Hazards from each source were assigned values for likelihood, with the largest for tephra fall from all sources, earthquakes and ground deformation, lava flows, scoria fall and base surge for an Auckland eruption on land, and earthquakes and ground deformation from an Auckland eruption in the ocean. The largest values for extent were for tephra fall and climate variation from each of the distal centres. However, these parameters do not give a true indication of risk. In a companion paper the effect of each hazard is fully investigated and the risk ranking completed.     

The crystal chemistry of lithium and Fe3+ in synthetic orthopyroxene

Lithian ferrian enstatite with Li₂O = 1.39 wt% and Fe₂O₃ 7.54 wt% was synthesised in the (MgO–Li₂O–FeO–SiO₂–H₂O) system at P = 0.3 GPa, T = 1,000°C, fO₂ = +2 Pbca, and a = 18.2113(7), b = 8.8172(3), c = 5.2050(2) Å, V = 835.79(9) Å³. The composition of the orthopyroxene was determined combining EMP, LA-ICP-MS and single-crystal XRD analysis, yielding the unit formula ^M2(Mg_0.59Fe _0.21 ²⁺ Li_0.20) ^M1(Mg_0.74Fe _0.20 ³⁺ Fe _0.06 ²⁺ ) Si₂O₆. Structure refinements done on crystals obtained from synthesis runs with variable Mg-content show that the orthopyroxene is virtually constant in composition and hence in structure, whereas coexisting clinopyroxenes occurring both as individual grains or thin rims around the orthopyroxene crystals have variable amounts of Li, Fe³⁺ and Mg contents. Structure refinement shows that Li is ordered at the M2 site and Fe³⁺ is ordered at the M1 site of the orthopyroxene, whereas Mg (and Fe²⁺) distributes over both octahedral sites. The main geometrical variations observed for Li-rich samples are actually due to the presence of Fe³⁺, which affects significantly the geometry of the M1 site; changes in the geometry of the M2 site due to the lower coordination of Li are likely to affect both the degree and the kinetics of the non-convergent Fe²⁺-Mg ordering process in octahedral sites.     

DEM与地形分析的并行计算

总结了数字高程模型构建、特征提取等并行算法的研究进展,概述了不同并行算法的主要内容;探讨了DTA并行技术在海量地形数据可视化和高性能地学计算的应用,随着DEM的需求日益增大,高精度、高分辨率DEM产品及其附加服务也逐步产品化。最后,通过分析并行计算发展的关键问题,提出DTA并行技术的研究趋势及研究意义,合适的数据划分和结果融合策略、通用并行算法、容错机制和负载均衡策略的设计是今后研究的重要内容,尤其是如何在多种计算模式共同发展的背景下利用并行计算解决地学难题,从而得到更接近现实世界地理环境的模拟,并扩大数字地形分析的应用范围。     

外来入侵植物分布格局及与环境和人为因子的关系——以五个自然保护区为例(英文)

以5个保护区为例来探究外来入侵植物与环境及人为因子间的关系。利用CCA分析了环境变量与外来入侵植物丰度的关系,采用了多元回归得出了与外来入侵植物最为相关的环境与人为因子。结果显示,从泰山自然保护区到丰林自然保护区,外来入侵植物分别为25种、12种、13种、5种、5种,沿着包括纬度、最高温度,最低温度、最高降雨量等环境因子强度的降低而下滑。而同时,外来入侵植物的数量随着人为活动的干扰度增强而增加。从起源上来看,热带成分从31%降至0,而北美起源的植物则逐渐增加。从科的组成上看,五个自然保护区中均有菊科分布,所占比例分别为15%、33%、36%、 40% 和20%,显示了其世界广布的特性,而其他科属入侵植物的分布并不均衡。从生活型上看,一年生或多年生草本植物为主要成分。外来入侵植物的传入途径在很大程度上受人类活动及利用喜好的驱动。