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611.
Previous research has shown that designers' and architects' evaluations of visual stimuli, and of urban and rural environments are not necessarily shared by non-designers and non-architects. Such conclusions may be biased by instrumentation and methodological problems, namely, previous instruments often require verbal responses about stimuli. Hence, non-designers and non-architects may be less capable in expressing themselves, but perceive the same things as the professionals. Another problem stems from professionals who have a narrow range of traits being compared with a general population that has a broader range of traits and therefore has greater within-group variance. This study presents an instrument and a methodology for dealing with these problems in addition to examining the perceptual orientations of architects in comparison to three other professions. Results indicate that architects varied from the other professional groups in their quantitative judgments of the habitats studied but not from all groups in their qualitative judgments. Hence, architects may be a distinct professional culture for some design variables only.  相似文献   
612.
Electron paramagnetic resonance (EPR) spectrometry has been used to study diesel particulate matter. The EPR signals for a graphitized carbon black and particles collected from two different diesel engines have been compared. Variations in the line widths and signal intensities due to various chemical and physical pretreatments of the particles were observed. The EPR signals for the diesel particulates were shown to be sensitive to oxygen, nitric oxide, nitrogen dioxide, and ultraviolet and visible radiation. These results suggest that EPR may be a convenient means for characterizing particles from different sources or for demonstrating particle reactivities. The demonstrated photochemical reactivities of the airborne particles have significant environmental health implications.  相似文献   
613.
Lead levels in the waters and sediments of the lake of the International Institute of Tropical Agriculture, Agodi Lake, Oba Lake, at three stations on Ogunpa stream, and at three stations on Ona River were measured from October 1977 to June 1978, using the combined APDC-MIBK-flame atomic absorption spectrophotometry technique. The lead levels recorded ranged from 0.2 to 46 μg/L for the aqueous phases; however, the levels in the sediments were much higher, ranging from about 18 to 85 mg/kg (dry weight). Although there is nothing alarming about these levels, the levels of lead in water bodies located in areas with high traffic density were consistently higher than levels for comparable waters in low traffic density areas. Similarly, lead levels were significantly higher in the fresh sediments of water bodies in areas with high traffic density, clearly indicating the onset of lead pollution for those high traffic density areas.  相似文献   
614.
Some 20 elements were determined in cow hair sampled in farms located in various industrial and rural zones of Belgium. Apart from the well-documented dependence of hair contamination as a function of age, the most characteristic feature observed in this study is that the high correlations existing between concentrations of some elements in cow hair provide inter-element ratios which significantly vary from one farm to another. These variations parallel the variations observed in the air pollutants deposited on grass while the inter-element ratios remain almost constant in the soils of all the sampling sites. As a consequence, it is proposed that elemental deposition on pastures is the main source of contamination of cattle by these elements, at least in the rural sites of industrialized countries such as Belgium.  相似文献   
615.
为了解尺寸对球形容器连接管道甲烷-空气混合物爆炸的影响规律,利用Fluent软件,采用κ-ε湍流模型、涡耗散模型(简称EDC模型)、壁面热耗散、热辐射模型及SIMPLE算法,建立了球形容器连接管道内甲烷-空气混合物爆炸的数值模型,对容器与管道内甲烷-空气预混气体爆炸的尺寸效应进行了数值模拟。结果表明:随管道内径增大,球形容器内最大爆炸压力逐渐增大,管道末端最大爆炸压力变化无明显规律;而随管道长度增加,球形容器内最大爆炸压力逐渐减小;改变管道内径,较大体积球形容器内最大爆炸压力均大于较小体积球形容器内最大爆炸压力,最大爆炸压力上升速率的规律则相反,容器体积对管道末端最大爆炸压力的影响无明显规律。  相似文献   
616.
Objective: Statistics indicate that employees commuting or traveling as part of their work are overrepresented in workplace injury and death. Despite this, many organizations are unaware of the factors within their organizations that are likely to influence potential reductions in work-related road traffic injury.

Methods: This article presents a multilevel conceptual framework that identifies health investment as the central feature in reducing work-related road traffic injury. Within this framework, we explore factors operating at the individual driver, workgroup supervisor, and organizational senior management levels that create a mutually reinforcing system of safety.

Results: The health investment framework identifies key factors at the senior manager, supervisor, and driver levels to cultivating a safe working environment. These factors are high-performance workplace systems, leader–member exchange and autonomy, trust and empowerment, respectively. The framework demonstrates the important interactions between these factors and how they create a self-sustaining organizational safety system.

Conclusions: The framework aims to provide insight into the future development of interventions that are strategically aligned with the organization and target elements that facilitate and enhance driver safety and ultimately reduce work-related road traffic injury and death.  相似文献   

617.
选取内蒙古生态脆弱区荒漠草原典型禁牧区和草畜平衡区进行对比研究.结合区域基本生态社会经济状况,设计了草场治理的选择实验问卷,使用Mixed Logit模型,分析牧民参与草场治理的偏好与支付意愿,以支付意愿作为牧民从草原生态改善中获得效用的测算依据,最终通过总体福利分析提出了相应的补偿标准.结果表明,两区牧民对于草场治理的偏好存在差异,禁牧区牧民的支付意愿显著高于草畜平衡区.禁牧区补偿标准最低应为0.57元/hm2,草畜平衡区补偿标准0.23元/hm2.禁牧区牧民偏好景观建设,而草畜平衡区牧民偏好地下水位上升.  相似文献   
618.
引黄调水对汾河受水区水环境的影响   总被引:1,自引:0,他引:1  
引黄入晋工程缓解了太原市水短缺问题。然而,近年来上游黄河水出现较严重污染。引黄调水对汾河受水区的影响尚不明确。论文基于连续观测和采样,分析了受水区河水、地下水水文过程、理化性质、主要离子、典型污染物邻苯二甲酸二丁酯以及大肠杆菌的含量和变化。结果表明:受水河流和河岸带地下水受引黄影响十分明显,含盐量和有机物含量显著增加,水环境整体退化;引黄导致汾河雨季高水位而旱季低水位的水文过程反转,且整个水文年内河水以饱和输水的方式补给浅层含水层,水位埋深变浅;汛期河谷发生洪水的风险大大增加;引黄导致汾河水电导率增大两倍左右,且河水由Ca-HCO3型变为Na-Cl·SO4型,而溶解有机碳含量增高约26%,UV254含量增大约24%;引水暂停期汾河水水化学特征趋于恢复,而河岸带地下水水化学特征未能恢复。长期来看,若引黄调水持续向河谷地下水输入大量Na+和Cl-等,且地下水埋深持续保持在较浅的范围,可能造成土壤盐碱化、植被退化和生态环境恶化等更加严重的后果。  相似文献   
619.
船体钢海水腐蚀研究进展   总被引:3,自引:3,他引:0       下载免费PDF全文
介绍了船体钢在海水中的腐蚀行为,总结了影响船体钢耐蚀性的因素及其改善耐蚀性的方法,总结了船体钢耐海水腐蚀性能研究、测试的试验方法,分析了试验方法对评价船体钢耐蚀性的适用性,指出了当前船体钢耐海水腐蚀性能研究的问题。  相似文献   
620.
南水北调对湖北丹江口水库区土地资源的影响   总被引:7,自引:1,他引:6  
湖北省丹江口水库区是南水北调中线工程的水源区。随着调水工程的实施,库区土地资源将受到深远的影响。以丹江口水库及其四周海拔低于200m的区域为研究范围,选用90年代初获取的LandsatTM假彩色合成图像为主信息源,运用目视判读和地理信息系统(GIS)方法,对该区的土地资源利用现状进行了比例尺为25万分之一的遥感制图和计算机面积量算;在此基础上,对工程实施后本区土地资源的淹没损失、土地利用结构的变化进行了宏观分析,进而对区域土地资源的合理利用进行了初步探讨。  相似文献   
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