应用模糊数学方法计算软科学成果的应用率

本文根据软科学成果应用中存在着不同应用程度的特性,提出了应用度的概念,并总结出一种应用模糊概率的方法计算软科学成果应用率的程序和方法.应用该方法对沈阳市1981—1990年期间的环保科研软科学成果应用率进行了统计分析和计算,并与传统应用率计算结果进行了比较.     

软土地基上生活垃圾卫生填埋场的岩土工程问题与对策

生活垃圾卫生填埋场是处理固体废弃物的有效方法之一.尽管国内外学者对与垃圾填埋场相关的许多问题已经做了大量的研究工作,但是对软土地基上填埋场可能引起的一些岩土工程问题研究不多.针对软土地基上的填埋场,分析了填埋场在建设与运营过程将会遇到的若干岩土工程问题.针对填埋场的沉降、稳定性等问题,提出了将垃圾荷载看作变量对地基沉降进行计算和设计.考虑垃圾体的稳定性,分析由于地基破坏而引起的整体稳定性问题和变形引起的衬里系统的内部稳定性问题,研究地基处理的可行性和适应性,并加强填埋过程中的岩土工程监测工作.     

The effect of entrapped nonaqueous phase liquids on tracer transport in heterogeneous porous media: laboratory experiments at the intermediate scale

This work considers the applicability of conservative tracers for detecting high-saturation nonaqueous-phase liquid (NAPL) entrapment in heterogeneous systems. For this purpose, a series of experiments and simulations was performed using a two-dimensional heterogeneous system (10x1.2 m), which represents an intermediate scale between laboratory and field scales. Tracer tests performed prior to injecting the NAPL provide the baseline response of the heterogeneous porous medium. Two NAPL spill experiments were performed and the entrapped-NAPL saturation distribution measured in detail using a gamma-ray attenuation system. Tracer tests following each of the NAPL spills produced breakthrough curves (BTCs) reflecting the impact of entrapped NAPL on conservative transport. To evaluate significance, the impact of NAPL entrapment on the conservative-tracer breakthrough curves was compared to simulated breakthrough curve variability for different realizations of the heterogeneous distribution. Analysis of the results reveals that the NAPL entrapment has a significant impact on the temporal moments of conservative-tracer breakthrough curves.     

Too small to count? Making Land Use Transformations in Chiquitano communities of San Ignacio de Velasco,East Bolivia,visible

ABSTRACT

The Santa Cruz lowlands, east Bolivia, are one of South America’s most dynamic agricultural frontiers. In the Chiquitania, bordering Brazil, San Ignacio de Velasco was in 2017 ranked first nationally in terms of deforestation. There, two deforestation fronts meet with mechanized agriculture expanding from the West and South and cattle ranching from the East. Chiquitano communities are demographically dominant locally but often face land scarcity. Because of their comparatively low impact on forest vegetation, they are not well represented in broad-scale quantitative Land Use/Land Cover (LULC) studies. Based on an empirical, human geographical approach, this paper investigates the transformation of the local indigenous productive matrix, the associated land-use patterns and potential socio-ecological implications. The overall aim is to bear witness to the rapid and profound reconfiguration of traditional livelihoods with their integration in the market economy and to highlight the significance of micro-scale LULC-processes at global scale.     

活性有机碳含量在凋落物分解过程中的作用

土壤凋落物的分解不仅是生态系统养分循环的重要环节,也是生态系统碳释放源之一。将呼伦贝尔森林草原过渡带的草原凋落物、白桦林凋落物、落松林凋落物分别添加在棕色针叶林土里进行恒温培养,探讨了不同凋落物类型有机碳分解速率差异及其影响因子。结果表明:不同凋落物的有机碳矿化速率和矿化累积总量在分解初期不一致,但由高到低的次序均为:草原凋落物→白桦林凋落物→落叶松林凋落物,40d的有机碳矿化累积量分别为76.53、47.42、20.56mg/g。这主要与凋落物的化学性质有关,主要决定于凋落物中易被微生物分解的热水溶性有机碳含量和易分解有机物含量,而与凋落物的总有机碳含量、全氮含量、w(C)/w(N)比等关系不明显。     

Paternity and condition affect cannibalistic behavior in nest-tending bluegill sunfish

Theory of parental care evolution predicts that a parent should invest more in a brood when its fitness value is greater than alternative investments such as the parent's own survivorship or future broods. In fish, filial cannibalism (eating one's own offspring) is widespread and represents a challenge to parental care evolution. In this study, I investigated filial cannibalism in bluegill sunfish (Lepomis macrochirus). Bluegill are characterized by alternative mating tactics referred to as "parentals" and "cuckolders". Parentals delay maturation, construct nests, court females and provide sole parental care for the developing offspring. Cuckolders mature precociously and parasitize parentals using two tactics called "sneakers" and "satellites". I found that parentals that obtained fewer eggs during spawning appeared more likely to completely cannibalize their brood (total filial cannibalism: P=0.07), regardless of their condition. Among parentals that provided care, partial cannibalism was greater during the egg phase as compared to the fry phase of care, but it was unrelated to brood size. Throughout the care period, parentals in better condition were less likely to partially cannibalize their brood, indicating that parentals use cannibalism to replenish energy reserves. Independent of condition, parentals that were cuckolded more were more likely to eat part of their brood. This relationship was evident only after the eggs had hatched, which is consistent with data showing that parentals can use olfactory cues produced by fry but not eggs to assess their paternity. This latter result proposes that parentals may be selectively culling cuckolder offspring from their nest. These data provide empirical support for parental care theory, and the first evidence for the importance of paternity on cannibalistic behavior.Communicated by M. Abrahams     

COPING WITH A SEVERE SUSTAINED DROUGHT ON THE COLORADO RWER: INTRODUCTION AND OVERVIEW1

ABSTRACT: In arid regions of rapid economic and population growth, adverse effects of droughts are likely to be increasingly serious. This article presents an introduction and overview of the papers collected in this special issue of the Water Resources Bulletin. The papers report on the second phase of a study of the impacts of and responses to a potential severe sustained drought in the Colorado River Basin in the southwestern U.S. The analyses were performed by a consortium of researchers from universities and the private sector located throughout the Basin. Tree ring studies suggest that droughts of duration and magnitude much more serious than any found in the modern records probably occurred in the Basin during earlier centuries. Taking the present-day configuration of the storage and diversion structures and the economic conditions in the Basin as the base-point, the general objectives of the study are three: first, to define a representative Severe Sustained Drought (SSD) and assess its hydrologic impacts; second, to forecast the economic, social and environmental impacts on the southwestern U.S.; and finally, to assess alternative institutional arrangements for coping with an SSD. The evaluation of impacts and policies was conducted with two distinct modeling approaches. One involved hydrologic-economic optimization modeling where water allocation institutions are decision variables. The second was a simulation-gaming approach which allowed “players” representing each basin state to interact in a real-time decision making mode in response to the unfolding drought.     

Developing sustainable agricultural systems for small farmers in Latin America

The great majority of farmers in Latin America are peasants who still farm small plots of land, usually in marginal environments utilizing traditional and subsistence methods. The contribution of the 16 million peasant units to regional food security is however substantial. Research has shown that peasant systems, which mostly rely on local resources and complex cropping patterns, are reasonably productive despite their small land endowments and low use of external inputs. Moreover analysis of NGO-led agroecological initiatives show that traditional crop and animal systems can be adapted to increase productivity by biologically re-structuring peasant farms which in turn leads to optimization of key agroecosystem processes (nutrient cycling, organic matter accumulation, biological pest regulation, etc.) and efficient use of labour and local resources. Examples of such grassroots projects are herein described to show that agroecological approaches can offer opportunities to substantially increase food production while preserving the natural resource base and empowering rural communities.     

Site search and multicriteria evaluation

Geographic information systems (GIS) are potentially powerful collections of tools which planners can use in the manipulation and analysis of spatial information. One traditional area of interest in this context is site search. Here, the functionality of GIS is, however, limited to certain deterministic analyses which serve merely as a computerised automation of the manual sieve mapping approach. The integration of multicriteria evaluation (MCE) techniques with GIS, is forwarded as a means of providing the user with the means to evaluate sites identified by sieve mapping techniques on the basis of multiple and conflicting criteria and objectives. An example application based on the search for suitable radioactive waste disposal sites in Britain using the Arc/Info GIS is included. The potential use of a combined GIS/MCE approach in the development of spatial decision support systems (SDSS) is considered.     

A new policy‐related measure of population dispersal and sparsity using GIS

Policy indicators applied at a national scale can have considerable financial impact for resource allocations to individual counties, especially if there are extreme local factors. This article develops arid explores a new measure of population dispersal and sparsity and discusses the impact of this indicator in a variety of locations, by using GIS techniques.