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81.
82.
Use of Maryland Biological Stream Survey Data to Determine Effects of Agricultural Riparian Buffers on Measures of Biological Stream Health 总被引:1,自引:0,他引:1
This study was undertaken to determine the importance of riparian buffers to stream ecology in agricultural areas. The original
Maryland Biological Stream Survey (MBSS) data set was partitioned to represent agricultural sites in Maryland's Coastal Plain
and Piedmont regions. ANOVA, multiple linear regression (MLR), and CART regression tree models were developed using riparian
and site catchment landscape characteristics. MBSS data were both stratified by physiographic region and analyzed as a combined
data set. All models indicated that land management at the site was not the controlling factor for fish IBIs (FIBI) at that
site and, hence, using FIBI to evaluate site-scale factors would not be a prudent procedure. Measures of instream habitat
and location in the stream network were the dominant explanatory factors for FIBI models. Both CART and MLR models indicated
that forest buffers were influential on benthic IBIs (BIBI). Explanatory variables reflected instream conditions, adjacent
landscape influence, and chemistry in the Coastal Plains sites, all of which are relatively site specific. However, for Piedmont
sites, hydrologic factors were important, in addition to adjacent landscape influence, and chemistry. Both Coastal Plain and
Piedmont CART models identified several hydrologic factors, emphasizing the dominant control of hydrology on the physical
habitat index (PHI). Riparian buffers were a secondary influence on PHI in the Coastal Plain, but not in the Piedmont. Between
40% and 70% of the variation in FIBI, BIBI, and PHI was explained by the “easily obtainable” variables available from the
MBSS data set. While these are empirical results specific to Maryland, the general findings are of use to other locations
where the establishment of forest buffers is considered as an aquatic ecosystem restoration measure. 相似文献
83.
在文献检索和访谈的基础上,提出有关编制适用于我国小学生水域安全调研的知信行(KAP)问卷的理论构想。以此为基础,编制小学生水域安全知信行初始问卷。经初测(N=495)和正式测量(N=2 554),运用探索性因素分析方法筛选条目,用克朗巴赫法评价同质性信度,据内容效度比评价内容效度,用探索性和验证性因素分析方法评价结构效度。问卷包含4个维度(水域安全知识、技能、态度和高危行为)共39个条目。问卷的信效度检验结果表明,问卷的因素结构、同质性信度、内容效度和结构效度均达到心理测量学的要求。小学生水域安全知信行问卷具有较为满意的信、效度,较好地反映了问卷设计的理论构想。 相似文献
84.
The limited and sporadic interaction between EIA and planning theory has meant that EIA has largely failed to benefit from planning theory insights and lessons. Obstacles and dilemmas already encountered and addressed in planning theory are still hampering EIA theory building and practice. An overview of the characteristics, strengths, and limitations of five major planning theories—rationalism, pragmatism, socio-ecological idealism (SEI), political-economic mobilization (PEM), and communications and collaboration (CC) is presented in an effort to ameliorate this problem. EIA parallels to each planning theory and lessons for EIA are identified. Also addressed are the application of planning theories to different context types, overlaps, interconnections and middle ground concepts among theories, the integration of values, ethics, and postmodern perspectives and the potential to construct composite theories. 相似文献
85.
Philip R. Reilly 《黑龙江环境通报》2009,29(9):829-832
The recently enacted federal law, the ‘Prenatally and Postnatally Diagnosed Conditions Awareness Act’ (United States Public Law 110–374) seeks to improve opportunities for parents and pregnant women to anticipate and understand the likely life course of children born with Down syndrome and other (unspecified) conditions. The law is in part a response to the continued growth of prenatal screening and testing. For example, the American College of Obstetricians and Gynecologists' Practice Bulletin 77 recommends that ‘Screening and invasive diagnostic testing for aneuploidies be available to all women who present for prenatal care before 20 weeks of gestation regardless of maternal age.’ Emerging technologies anticipate an era in which the scope of prenatal screening and testing will be much larger than it is today. Inevitably, more women will find themselves facing the hard question of whether to continue or end a pregnancy in which a fetus has been found to have a significant abnormality. While the new federal law is not likely to have a major impact on obstetric practice, it may be a harbinger of renewed wide-scale public debate concerning the ethics of prenatal screening. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
86.
干式脉冲煤气布袋除尘作为“十五”国家重点推进的40项冶金节能环保技术的措施之一,成为国内在建高炉优先选择的工艺技术,也是目前高炉改造湿法除尘工艺的技术方向,近几年此技术已成功应用于各大型高炉。较湿法除尘相比各类效益明显,已成为今后大型高炉煤气除尘技术发展的趋势,安钢6#、7#高炉(450 m^3)自使用该技术以来,经过实践摸索,逐渐取得了一些较先进的经验。 相似文献
87.
安全工程专业生产实习模式探讨与实践 总被引:5,自引:0,他引:5
生产实习作为安全工程专业教学计划的重要环节,有助于培养学生的工程意识、应用能力和创新能力.基于中国石油大学(华东)在安全工程专业生产实习的实践教学环节上所做的探索性工作,对如何有效提高该环节的培养效果进行了分析和总结. 相似文献
88.
我校从2005年开始在大一年级试实施分级教学,一个学期的教学实践证明我们的改革是可行的,我们的分级教学取得了初步的效果。 相似文献
89.
王彬辉 《中国环境管理干部学院学报》2000,(2)
长期以来,我国对排污或超标排污实行征收排污费制度。九届人大常委会第13次会议修订通过的《海洋环境保护法》对此进行了改革。本文对此进行了深入分析。 相似文献
90.
中国可持续发展进展及其理论研究的若干思考 总被引:13,自引:1,他引:12
用可持续发展理论指导实践,建立理论与实践互动关系,是当前我国实施可持续发展战略的重要问题,本文总结了我国可持续发展理论与实吓的重要进展,指出了近期理论研究的重要内容,并提出了相应的建议。 相似文献