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61.
用实验室模拟的方法着重研究硅藻的角刺藻(Chaetocerosgracilis)和乳游甲菏的前沟藻(Amphidimiumhoeflier)生长过程中DMS的生产及不同氮营养条件下对前沟藻DMS生产的影响。结果表明(1)前沟藻和角刺激都可以生产二甲基硫(DMS),但2者DMS生产能力有很大差别,前沟藻DMS平均生产率大约是角刺激藻的100倍。(2)不同生理阶段的DMS产量不同。对数增生匠前沟藻细胞  相似文献   
62.
At work, people may experience fatigue and a depletion of mental resources. The subsequent need for recovery is generally assessed employing subjective reports on evaluative statements. In this paper, we explore whether it is possible to assess employees’ recovery needs with a systematic inspection of behaviors. The idea is based on Campbell’s paradigm (Kaiser, Byrka, & Hartig, 2010), which holds that individuals will perform more, and more difficult behaviors to recover from fatigue when their need for recovery is higher.  相似文献   
63.
Sediments from Polish coastal environments were classified by a quality assessment approach that took into account trace metal and organic micropollutant concentrations, grain-size distribution, and organic carbon content. Generally, no benthic organisms were found at sites where sediments were classified as heavily polluted. However, areas characterized by a moderate contamination showed a variable composition of the benthic community and changing bioaccumulation patterns; therefore, no single species found in the Gulf of Gdańsk could be considered representative of the whole benthic environment. Although sediment monitoring must be considered a suitable tool to detect hot-spot pollution areas in coastal and inland waters, it should be complemented by bioaccumulation measurements to evaluate the actual risk posed by contaminants to benthic organisms. This “biological information” allows a better appreciation of the real benthic infaunal community exposure to chemicals and can usefully complement the existing sediment quality guidelines.  相似文献   
64.
Environmental justice sheds light on the distributive and procedural aspects of planning and decision-making. We examined the challenges arising from the perspective of environmental justice on multi-level and participatory environmental governance by exploring the governance of aquatic environments in the Helsinki Metropolitan Area. We found three main challenges and potential responses to them. First, even though most of Helsinki’s shoreline is free and/or accessible by road and accordingly used actively by people for recreational purposes, many parts of the shoreline are perceived as inaccessible, reflecting a need to combine factual and perceived accessibility of aquatic environments in detail during the planning processes and to discuss reasons for possible discrepancies between these two. Second, there was a remarkable seasonal variation in the use of aquatic environments, so more attention should be paid to social-demographic factors explaining the distribution of the use of urban nature. Third, it seems to be difficult to capture the variety of perceptions of people and to integrate them into planning and decision-making processes even on a local scale, and this challenge is likely even more pronounced on higher levels of planning and governance. Thus, better integration of regional and local-scale planning procedures should be encouraged. Building on these observations, we conclude that integration of procedural and distributive environmental justice into the practices of the governance of aquatic environments could remarkably decrease unwanted trade-offs and potential conflicts in their use and management.  相似文献   
65.
有机污染物多介质环境的稳态非平衡模型   总被引:2,自引:1,他引:2       下载免费PDF全文
在稳态平衡模型的基础上,研究了有机污染物在多介质环境的稳态非平衡模型,并针对DDT、1,2,4,-TCB、HCB、PCB和DMP5种化合物进行了计算。结果表明,该模型只须通过污染物在水中的浓度以及该化合物的各种物理化学性质和环境参数就可计算环境各相中污染物的浓度、逸度和质量分布,从而预测污染物在多介质环境中的归趋。  相似文献   
66.
莱州湾盐度变化现状及其对海洋环境与生态的影响   总被引:1,自引:0,他引:1  
依据莱州湾生态监控区2004年5、8月份两个航次的盐度监测资料,结合近40a污染监测网莱州湾海域的监测资料和历年黄河入海径流量等有关资料,研究分析了近年莱州湾盐度变化状况及主要影响因素。研究发现近40 a莱州湾盐度变化趋势总体上呈上升态势,莱州湾盐度值与以前相比有明显升高。黄河径流量锐减和断流是引起莱州湾盐度升高的主要原因。莱州湾盐度升高,对莱州湾海洋生态环境的影响是多方面的,对湾内产卵场、育幼场和海洋生物群落结构都有一定的影响。  相似文献   
67.
本文在对西昆仑山广布的岩浆岩尤其是花岗岩研究取得的成果基础上 ,结合区域构造、沉积建造等其它地质特征 ,再造了西昆仑山地质构造发展历程 ,进而研究了区内成矿堆积环境及其矿床地质特征。结果表明 ,西昆仑山经历了复杂的地质构造演化 ,是一条由北而南分别由加里东造山带、华力西造山带和燕山早期造山带组成的复合型造山带。区内存在以下 5种主要成矿堆积环境 :洋脊 (蛇绿岩 )成矿堆积环境 (塞浦路斯型含铜黄铁矿矿床 ,豆荚状铬、镍矿床 ) ,被动陆缘成矿堆积环境 (MVT铅锌矿床 ,Sedex型铅铜矿床 ) ,火山弧成矿堆积环境 (斑岩型铜矿床 ,黑矿型铜锌铅矿床 ,矽卡岩型铜铅锌多金属矿床 ) ,弧后盆地成矿堆积环境 (海底火山喷发沉积型铁铜金矿床 ,气液充填型铜金铁矿床 )和同碰撞成矿堆积环境 (伟晶岩型稀有金属矿床 ,伟晶岩型多金属银矿床 )  相似文献   
68.
用实验室模拟的方法着重研究硅藻的角刺藻(Chaetocerosgracilis)和浮游甲藻的前沟藻(Amphidiniumhoefleri)生长过程中DMS的生产及不同氮营养条件下对前沟藻DMS生产的影响.结果表明:(1)前沟藻和角刺藻都可以生产二甲基硫(DMS),但2者DMS生产能力有很大差别,前沟藻DMS平均生产率大约是角刺藻的100倍.(2)不同生理阶段的DMS产量不同.对数增长期的前沟藻细胞释放DMS的能力最强,其DMS速率是指数增长期的3倍.静止期和衰老期的前沟藻细胞DMS的生产能力下降.(3)低氮条件对前沟藻细胞DMS有促进作用.其中低浓度组(0.5mg/LNaNO3)DMS产率是高浓度组(50mg/L)的4倍.  相似文献   
69.
The paper presents a quantitative engineering approach to analysis of total environment allowing for simultaneous consideration of a theoretically infinite number of quality indicators and physiological requirements. It discusses theory and fundamentals of a two-dimensional space and time function solution concerning a small estuarine-type environment. A three dimensional solution is indicated. Input data may range from reconnaissance-type to the outputs of mathematical transport models. Applications are discussed with respect to environmental quality problems, availability of suitable data, and some areas of research where results could find immediate application.  相似文献   
70.
等温层曝气器内表观水流速度直接影响等温层曝气的充氧效果,针对表观水流速度难以准确计算的普遍问题,系统分析了曝气室内气水两相流运动所受的驱动能量与损失能量,提出了尾涡和顶部能量损失的无量纲表达式,建立了曝气室内水流的一维水动力学模型,以及基于MATLAB真域算法的模型求解方法.采用美国Prince湖等温层曝气器的实际运行数据,对该模型进行了验证,表观水流速度的预测误差在±8%以内,明显低于现有预测误差±20%.当曝气孔直径为2.6mm、曝气量从0.018m3/h增加到0.063m3/h时,曝气室内表观水流速度随曝气量的增加而增加;当曝气量固定,曝气孔直径从2.6mm减小至0.26mm时,表观水流速度随曝气孔直径的减小而增加,而当曝气孔直径进一步减小至0.026mm时,表观水流速度基本不受影响.计算了不同条件下的驱动能量和各项损失能量,揭示了引起表观水流速度变化的内因.建立的水动力学模型可用于指导等温层曝气器的设计和优化.  相似文献   
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