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441.
本文介绍了成都麻羊品种特征、体型结构、生产性能及其产区概况,讨论了保种选育的方向、指标和种群建设规模;提出了规划保种区、建立良种繁育体系、组建保种核心群、严格选种选配、科学饲养、合理培育、健全卫生防疫制度等配套技术措施,以及强化管理、加强协作、扶持发展专业户、搞好技术培训、合理利用等组织措施。 相似文献
442.
Frank Dobrowolski Leonard Grillo 《Journal of the American Water Resources Association》1977,13(3):455-460
ABSTRACT: The current 201 study by the Bergen County Sewer Authority illustrates possibilities for improving the currently defined relationships between 201, 208 and 303 studies. The Bergen County Sewer Authority serves 115 square miles in northeast New Jersey, providing sewerage service to 507,000 people in 43 municipalities. Its STP discharges to the Hackensack River, a tidal estuary recently classified as Water Quality Limited, and which receives significant non-plant loading. The subject 201 study is concurrent with 208 and 303 planning by NJDEP. Preliminary evaluations show that detailed 201 work can affect the conclusions of 303 and 208 studies, and that a wider (environmental - social as well as economic) interpretation of cost-effectiveness can demand re-examination of prior assumptions and decisions, a task not typically part of 208–303 work. Increased flexibility is needed in applying 303 and 208 recommendations to defining 201 studies and NPDES permit criteria, particularly in analysis of water use objectives, water quality parameters and future flows, loadings and facility costs. Further, perception of alternatives can be clarified by broadening analysis of costs and control and plant strategies. Inclusion of 201 planning at all stages of regional planning can synergistically improve the total planning process. 相似文献
443.
A comprehensive framework for assessing and selecting appropriate scaffolding based on analytic hierarchy process 总被引:1,自引:0,他引:1
Problem: Bamboo scaffolding has been widely used in South China, Hong Kong, and Southeast Asia for many years. Bamboo scaffolding is more economical, but its safety record is relatively poor. Conversely, metal scaffolding is more expensive, but its use in these regions has increased in recent years because it is relatively safe. The assessment and selection of the most appropriate type of scaffolding for a particular construction project is always a concern for project managers. Method: This paper suggests a comprehensive assessment framework that enables project managers to take a number of major quantitative and qualitative factors into consideration when making scaffolding decisions. This framework is based on the Analytic Hierarchy Process methodology and a survey among project managers in Hong Kong. Results: The research reveals that the overall performance of metal scaffolding is believed to be better than bamboo scaffolding. A sensitivity analysis has also been conducted to investigate the impact of various factors on the final decisions. Impact on Industry: The proposed assessment framework can be used as a supporting tool for project managers in the selection of scaffolding for their projects. 相似文献
444.
445.
GONTRAN F. BAGE RÉJEAN SAMSON BERNARD SINCLAIR-DESGAGNÉ 《Environmental management》2002,30(6):0807-0815
A technicoeconomic model is developed to select an optimal strategy for the remediation of a contaminated site and to determine
the value of this remediation strategy. The model is an extension of actual cost–benefit analysis, with consideration of “irreversible”
remediation technology choices, technology effectiveness, and uncertainty on the site's level of contamination. The model
considers the possibility of reducing uncertainty by both acquiring more and better information on the level of contamination
and by offering the decision-maker the opportunity to reevaluate his decision and switch to a more appropriate technology.
It is believed that this model will help decision-makers in the selection of a remediation strategy by presenting all potentially
feasible strategies, and how uncertainty on the site's level of contamination affects these strategies. 相似文献
446.
A. V. Vecchia 《Journal of the American Water Resources Association》1985,21(5):721-730
Results involving correlation properties and parameter estimation for autoregressive-moving average models with periodic parameters are presented. A multivariate representation of the PARMA model is used to derive parameter space restrictions and difference equations for the periodic autocorrelations. Close approximation to the likelihood function for Gaussian PARMA processes results in efficient maximum-likelihood estimation procedures. Terms in the Fourier expansion of the parameters are sequentially included, and a selection criterion is given for determining the optimal number of harmonics to be included. Application of the techniques is demonstrated through analysis of a monthly streamflow time series. 相似文献
447.
448.
娱乐及餐饮业近年来发展迅速,开展这类项目的环境影响评价工作首先应确保其环保审批手续的前置性。环评单位应在项目筹划初期介入,工作中应以项目合理选址和提出具有可操作性的污染防治措施这两个侧重面开展工作,作出准确的评价结论,给出可行的污染防治措施及方案。只有这样,才能编制出较为完善的环境影响评价文件,才能达到预防或减轻不良环境影响的最终目的。 相似文献
449.
Economic theory asserts that to achieve maximum conservation benefits land acquisition needs to be cost effective. Yet the most common planning technique used by land conservation organizations is ‘benefit-targeting’ that focuses only on acquiring parcels with the highest benefits and ignores costs. Unlike most of the literature which focuses on covering problems, this research applies optimization techniques to achieve maximum aggregate conservation benefits for an ongoing land acquisition effort in the Catoctin Mountain Region in central Maryland. For this case study, optimization yields additional conservation benefits worth an estimated $3.1–$3.9 million or achieves the same level of conservation benefits but at a cost savings ranging from $0.9 to $3.5 million, depending on the initial budget size. Finally, the highest efficiencies are achieved in low budget scenarios, like those most prevalent in conservation efforts. 相似文献
450.
通过对一种国外应用较广的污泥虹吸系统的适应化改造可行性论证,对其实施了一种在改进效果、改造风险、改造难度以及成本方面都较优的改造方案。通过1a的试运行,整个系统运转正常,整体改造十分成功。 相似文献