有机食品的发展现状及趋势探讨

介绍了有机食品的概念,分析了国际有机食品运动的发展方向、推动因素和市场潜力,预测今后几年内全球有机产品市场的年平均发展速率为15％－20％。同时,还分析了我国发展有机食品的国际环境、农业基础和发展模式,认为发展有机农业和有机食品是跨越绿色贸易壁垒的良策,国内的消费市场潜力和空间巨大,预测到2010年,我国有机食品占国内食品市场的比例可望达到1.0%-1.5%,占全球有机食品市场的份额则可望达到3.0%。     

草地生态农业与产品革新是西北地区农业的出路

针对西北地区农业越来越依赖化肥、农药来提高产量以及污染问题日趋严重的现状 ,提出将发展草地生态农业与革新产品作为该地区农业可持续发展的出路。建议先主抓多途径开辟有机肥源 ,大田作物资源化增值 ,快速解决奶牛牛源与增加系统生物多样性 4项 ,可改善生态环境 ,使农民增收 ,将农业生态系统导入良性循环     

染料废水生物降解的产物分析

介绍了含酸性蒽醌蓝324染料废水在兼氧-好氧系统中的生物转化.产物分析结果表明:80.5%的母体染料大分子能在兼氧条件下降解成较为简单的中间产物,并且这些中间产物能在好氧条件下进一步矿化.对各反应器中主要的代谢产物分别进行紫外-可见、红外(FT-IR)和高效液相色-质联谱仪(HPLC-MS)检测分析后发现,母体染料经兼氧水解首先生成1-氨基-2-羟基蒽醌以及还原态的-OH基取代蒽醌隐色体,进一步水解生成3,4-二羟基苯甲酸.再经好氧处理,降解终产物中检测到了质荷比为101、102的脂肪类碳氢化合物、胺及醇等物质,未见有共轭结构存在.     

水中有机成分及其对饮用水质的影响

微量有机污染物和氯化消毒副产物对饮用水构成直接威胁,是饮用水中要重点控制的;天然大分子有机物对水质构成间接影响,导致胶体稳定性提高、增加药耗;藻类和代谢产物影响常规处理工艺效果,对水质产生不良影响。     

关于提高挥发酚测定质量的探讨

探讨了在水样采集及分析测定过程中，如何保证分析结果的可靠性和准确性。     

Measures of preferred direction for environmental and ecological circular data

Circular or angular variables indicating direction or cyclical time can be of great interest to scientists studying ecology, biology or environmental issues. A common problem of interest in circular data is estimating a preferred direction and its corresponding distribution. This problem is complicated by the so-called “wrap-around effect” on the circle, which exists because there is no natural minimum or maximum. The usual statistics employed for linear data are inappropriate for directional data, as they do not account for its circular nature. Three choices for summarizing the preferred direction (the sample circular mean, sample circular median and a circular analog of the Hodges–Lehmann estimator) are discussed, with examples from environmental and ecological applications. Similar to the linear data case, the relative emphases of different methods sometimes yield different measures of preferred direction in the presence of outliers or lack of symmetry in the original data. Received: November 2003 / Revised: June 2004     

A Multidisciplinary Approach to Assessing the Sustainability of Freshwater Crayfish Harvesting in Madagascar

Abstract:  There is growing interest among conservation decision makers in promoting harvesting of forest products as an incentive for communities to retain forest cover. Assessments of the sustainability of existing harvests are essential for implementing such policies. Madagascar's endemic freshwater crayfish, Astacoides spp., are harvested throughout their range. Despite their importance to human communities, Madagascar's crayfish, like much of the island's freshwater biodiversity, are poorly known, and there is concern that the harvest may be unsustainable. We investigated sustainability of the crayfish harvest in and around Ranomafana National Park in eastern Madagascar, focusing on the heavily harvested A. granulimanus. Several villages around the park have traditional taboos against selling crayfish, resulting in widely varying levels of crayfish exploitation. We used two approaches to assess sustainability of the harvest. First we used participatory mapping combined with a geographic information system analysis to produce a spatially accurate map of harvesting intensity. We then carried out mark-and-recapture sampling at 74 sites across a range of harvest intensities to test whether the level of harvesting was a significant predictor of crayfish density and structure. Second, we used size-structured matrix population models to estimate the forest area necessary to provide the observed annual harvest from one harvesting village and compared this estimate with the area available to the harvesters. Our findings show that the crayfish harvest in Ranomafana may be sustainable under current socioeconomic conditions, suggesting that A. granulimanus is less vulnerable to overexploitation than previously thought. We emphasize the importance of a multidisciplinary approach to assessing sustainability involving both ecological information about the harvested species and socioeconomic data about the level and spatial pattern of the harvest.     

On thresholds and environmental curve tensiometers

This paper considers distinctions between lognormal and mixture models. Emphasis is placed on two component mixtures where the lower valued subpopulation has a large mixing parameter. The density of this sort of mixture can be easily mistaken for a lognormal density. In order to compare such a mixture to a lognormal it is demonstrated that Galton's two parameter logmodel and Pearson's five parameternormal mixture are special, or limiting, cases of the same general mixture model. Consideration is given to the lognormal threshold parameter in order to devise a tool that can help distinguish mixtures from lognormals. Based on the threshold parameter, piloted procedures can help measure whether or not a curve is friable, in the sense that a brittle curve is better represented as a mixture than as a skewed lognormal. It is also shown that generalizations of Galton's product risk model can be represented interms of the threshold parameter Based on a tool called a curve tensiometer was designed to be applied as a graphical friability check in the ecological context of Fisher's classic Iris data and in the environmental context of a Santa Monica Bay fish consumption study.     

对现行监测结果报告规则的粗浅看法

监测结果的报告是整个环境监测工作的结晶。它要求必须实事求是，才能为环境管理提供科学依据。而现行的监测结果报告规则。存在着人为夸大和缩小两方面的弊端，低于检出限的监测结果的表述模糊。不能真实的反映监测对象的实际情况，对人们了解环境质量状况及环境容量不能提供准确依据。给环境管理与环境规划等工作造成误导，本文以实例作了说明，并提出解决的方法。     

窄脉冲电晕等离子体烟气脱硫产物收集研究

对窄脉总电晕等离子体烟气脱硫过程中的产物收集进行了研究与探讨，结果表明正脉冲流注电晕放电烟气脱硫过程中产生的电粉尘以及电晕极肥大等问题，对脱硫产物的收集有很大影响。