实验用水对总氮检测结果的影响

用RO纯水与超纯水分别作为实验用水,通过标准曲线及空白、标准样品、水样等总氮测定对比实验,发现两种实验用水的标准曲线及空白值、标准样品的检测均受控,但两种纯水对比实验显示相对于超纯水而言,RO纯水中有一定浓度的总氮,同时在水样检测中用RO纯水作实验用水测定值明显低于用超纯水作实验用水的测定值,其差值与RO纯水中总氮值相符。实验结果表明总氮检测中不能只以标准曲线、空白值和标准样品测定值作为受控标准,要考虑实验用水中硝酸根离子的影响。     

近岸和河口低氧成因及其影响的研究进展

近岸和河口区的富营养化加剧、赤潮频发和全球变暖是导致低氧加剧的主要原因。频繁发生的低氧事件和不断扩大的低氧范围对海洋生物个体甚至整个生态系统造成了严重的损害。文章结合近几年的研究报道,综述了近岸和河口低氧的形成原因,以及生物在分子水平、生化水平、个体水平以及生态系统水平上对低氧环境的响应。     

The optimal harvest and management in the models of animal populations

We extended zero-cost optimization model for population of domestic animals. Also the model of hiring of labor in cattle-breeding farm is constructed and investigated.     

Ecoagrochemical Approaches to the Problem of Nitrate Pollution in Agroecosystems

On the basis of long-term studies, the role of agricultural chemicals in enhancing the production process and the rate of nitrate accumulation in plants is shown. Their influence on the state of plants is evaluated from physiological and agrochemical standpoints. The possibility of improving the resistance of agroecosystems to various adverse factors is considered.     

Leadership: a New Frontier in Conservation Science

Abstract:  Leadership is a critical tool for expanding the influence of conservation science, but recent advances in leadership concepts and practice remain underutilized by conservation scientists. Furthermore, an explicit conceptual foundation and definition of leadership in conservation science are not available in the literature. Here we drew on our diverse leadership experiences, our reading of leadership literature, and discussions with selected conservation science leaders to define conservation-science leadership, summarize an exploratory set of leadership principles that are applicable to conservation science, and recommend actions to expand leadership capacity among conservation scientists and practitioners. We define 2 types of conservation-science leadership: shaping conservation science through path-breaking research, and advancing the integration of conservation science into policy, management, and society at large. We focused on the second, integrative type of leadership because we believe it presents the greatest opportunity for improving conservation effectiveness. We identified 8 leadership principles derived mainly from the "adaptive leadership" literature: recognize the social dimension of the problem; cycle frequently through action and reflection; get and maintain attention; combine strengths of multiple leaders; extend your reach through networks of relationships; strategically time your effort; nurture productive conflict; and cultivate diversity. Conservation scientists and practitioners should strive to develop themselves as leaders, and the Society for Conservation Biology, conservation organizations, and academia should support this effort through professional development, mentoring, teaching, and research.     

Autocorrelation offsets zero-inflation in models of tropical saplings density

Modelling the local density of tropical saplings can provide insights into the ecological processes that drive species regeneration and thereby help predict population recovery after disturbance. Yet, few studies have addressed the challenging issues in autocorrelation and zero-inflation of local density. This paper presents Hierarchical Bayesian Modelling (HBM) of sapling density that includes these two features. Special attention is devoted to variable selection, model estimation and comparison.     

Forecasting energy demand of China using Bayesian Combination model

To analyze the impact of the related economic factors on China's energy demand, Path analysis is used to analyze the major factors and their direct and indirect effects on energy demand. This study showed that the main factors that affect the energy demand are the economic growth, the total population, and the primary energy structure, the economic growth is the main determining factor, and the primary energy structure is the major restrictive factor. On this basis and considering the multicollinearity and the validity of the forecast, we established a partial least-square (PLS) and the trend extrapolation prediction model, and then we sum up all the information to found a PLS—trend extrapolation combination forecasting model based on the optimized combining forecast theory. Finally, we obtain the probability distribution of the error using the Bayesian statistic theory and find the confidence interval of combining forecasting result. The results indicate that the outcome of combining forecasting will be more precise after using the Bayesian error correction approach.     

四辊轧机横向刚度的理论计算

运用影响函数法,对不同工艺制度及轧机参数条件下的轧机横向刚度进行了理论计算及分析讨论.     

PLANNING METHODOLOGY FOR ANALYSIS AND MANAGEMENT ON LAKE EUTROPHICATION1

ABSTRACT: The effects of changing nutrient inputs through land use management, waste water treatment, or effluent diversion are not clear, and managers are discovering that decisions which were effective in reversing eutrophication for one lake are often unsuccessful when applied to another. Simple empirical relationships are often used to predict the impact of management decisions. Errors in estimation could result in either substantial costs for overdesign or failure to meet desired eutrophication levels. This paper presents and illustrates a methodology to evaluate the impact of land use and water resource management decisions on lake eutrophication. The problems of worth of additional information, and uncertainty of estimates were handled within a cost-effectiveness framework. The probability of exceeding a critical level of eutrophication was considered as a measure of effectiveness. The cost criterion is the expected value of opportunity costs, costs of analysis and costs of additional information. Uncertainty analysis techniques were used to estimate the effectiveness of various management alternatives. Bayesian methods can be utilized to determine the worth of additional information. The methodology was applied to Beseck Lake, Connecticut, and the cost and effectiveness measures estimated for a number of land management alternatives. Worth of additional information was not determined in this initial effort in uncertainty analysis for lake eutrophication management.