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381.
Quantitative analysis of siliceous microfossils in a 210Pb dated core from Green Bay of Lake Michigan shows clear evidence of eutrophication, but a different pattern of population succession than observed in the main deposition basins of the Great Lakes. Sediments deposited prior to extensive European settlement (ca A.D. 1850) contain high relative abundance of chrysophyte cysts and benthic diatoms. Quantity and composition of microfossils deposited during the pre-settlement period represented in our core is quite uniform, except for the 30–32 cm interval which contains elevated microfossil abundance and particularly high levels of attached benthic species. Total microfossil abundance and the proportion of planktonic diatoms begins to increase ca 1860 and rises very rapidly beginning ca 1915. Maximum abundance occurs in sediments deposited during the 1970's, with a secondary peak in the late 1940's — early 1950's. Increased total abundance is accompanied by increased dominance of taxa tolerant of eutrophic conditions, however indigenous oligotrophic taxa, particularly those which are most abundant during the summer, are not eliminated from the flora, as in the lower Great Lakes. It appears that a combination of silica resupply from high riverine loadings and replacement of indigenous populations by periodic intrusions of Lake Michigan water allow sequential co-existence of species usually exclusively associated with either eutrophic or oligotrophic conditions.  相似文献   
382.
Fougerite is a new iron oxide, a mixed M(II)–M(III) hydroxide, a member of the green rust group. Its structure consists of a brucitic layer of Fe(III)–Fe(II)–Mg(II), where the excess of the positive charge due to Fe3+ is compensated in the interlayer by anions. The limits of composition are structurally and geochemically constrained, and the stabilities of the mineral and green rusts are obtained by a thermodynamic model of a regular solid solution, for different compensating anions and for any allowed composition of the brucitic layer.  相似文献   
383.
In recent decades, the Taiwanese government has worked actively to implement the concept of a sustainable Taiwan. As an important step in their strategy, the Ministry of Education has decided to promote the Green School Partnership Project in Taiwan (GPPT). However, academic research and critical reflection on the effects of this environmental and sustainability education initiative are lacking. Therefore, this study focuses on filling this gap by means of a nationwide generalizable effect study. The sampling allowed comparisons between the sixth, ninth, and twelfth grades in GPPT and non-GPPT schools and considered the geographic location (north, center, and south of Taiwan) as well as socio-economic area of the schools. A total of 1741 students participated, answering a questionnaire that focused on student sustainability consciousness (SC) and its components (i.e., knowingness, attitudes, and behaviors in relation to sustainability). Data were analyzed through structural equation modeling. Our findings make an important empirical contribution, indicating that GPPT schools and non-GPPT schools have a similar effect on the SC of students, i.e. schools engaged in the GPPT do not enhance student SC. In addition, the gender gap regarding SC increased consistently with each increasing grade level, yielding higher mean values for the girls than for the boys. Furthermore, an adolescent dip occurred in the student SC, especially with regard to student sustainability behavior. Given these findings, implications for developing GPPT are discussed; this research could provide valuable information about the educational transformation process to enhance environmental and sustainability behavior among students in Taiwan.  相似文献   
384.
文章构建海洋科技绿色创新两阶段模型,将网络超效率EBM模型和DEA窗口分析相结合测度了我国沿海地区2008—2017年海洋科技绿色创新整体和分阶段效率。结果显示:考察期内整体效率均未实现DEA有效,研发与转化阶段的低效是其内在原因;整体效率与研发效率变化趋势高度相似;区域间效率水平差异比较明显,2011年后整体及阶段效率水平均呈现“东部较高、南部次之、北部较低”的态势;研究期内“高研发高转化”型地区仅有江苏、浙江、广东。  相似文献   
385.
2008 年与2009 年黄海绿潮漂移路径分析   总被引:2,自引:0,他引:2  
利用卫星资料分析了2008年和2009年黄海绿潮的漂移路径的差异,基于QSCAT(Quick Scatterometer)卫星风场及海洋模式表层环流模拟结果,分析了绿潮漂移路径差异的动力机制。结果表明:2008(2009)年绿潮发生期间黄海海域以南东(偏南)风为主,江苏至山东半岛南岸海域表层平均流为偏北(东北)向,青岛附近海域低频余流为偏西(东)向流,致使绿潮的漂移方向为西北(东北)向,在青岛(烟台-威海)近岸海域发生聚集。2008年和2009年绿潮漂移路径差异,主要由海面风与表层环流的共同作用引起。通过对黄海海域海面风场和表层流场的早期预报,可以提前预判绿潮的影响区域和程度,为政府相关部门防灾减灾工作提供决策支持。  相似文献   
386.
邱宏喜 《地质与勘探》2014,50(Z1):1406-1412
本文采用HCl-HNO3-NH4HF2-KClO3封闭溶样,在(NH2)2CS介质中,原子吸收光谱法测定矿石中的Au、Ag。方法能有效避免AgCl、PbCl2沉淀和Au、Ag的硅酸盐包裹体,以及W、Mo和Sb、Pb等在Au富集过程中的竞争吸附与容量法测定的终点干扰。应用ICP-AES可在该介质中完成金矿样品中Ag、Cu、Pb、Zn、As、Sb等的同时测定。方法绿色环保,操作简单、快速,稳定性好,准确度和精密度高,适合于大批量金矿样品的分析测定。  相似文献   
387.
SH波作用下浅埋裂纹附近半圆形凸起的地震动   总被引:2,自引:0,他引:2  
利用Green函数、复变函数及多极坐标法研究了浅埋裂纹附近的半圆形凸起地形对SH波的散射问题。首先求解出适合本问题的Green函数,即含有半圆形凸起的弹性半空间内任意一点承受时间谐和的出平面线源荷载作用时位移场的解答。然后,从半圆形凸起地形对SH波的散射问题出发,利用本问题的Green函数在基体内构造裂纹。最后给出了浅埋裂纹附近的半圆形凸起地形对SH波散射的位移场。通过算例讨论了裂纹对地表位移幅值的影响,结果表明裂纹在一定情况下具有减震作用。  相似文献   
388.
Over the last decade, hundreds of climate change adaptation projects have been funded and implemented. Despite the importance of these first-generation adaptation projects for establishing funders and implementors’ “best practices,” very little is known about how early adaptation projects have endured, to what ends, and for whom. In this article, I propose a community-based methodology for ex-post assessment of climate change adaptation projects. This methodology contributes to recognitional justice by asking the individuals and collectives tasked with sustaining adaptation initiatives to define adaptation success and what criteria for success should be assessed. I apply this subjective assessment approach in 10 communities across Ecuador that participated in an internationally funded adaptation project that concluded in 2015. My analysis draws together participatory mapping, walking interviews with local leaders, participant observation, and surveys with former project participants. The results highlight that even adaptation projects that were deemed highly successful at their closure have uncertain futures. I find that the sustainability mechanisms that were envisioned by project implementors have not functioned, and communities are shouldering the burden of reviving failing adaptation interventions. These findings highlight that the current model of episodic funding for climate change adaptation projects and evaluation processes needs to be revisited to acknowledge the long-term challenges faced by communities. This analysis also calls attention to the importance of ex-post assessment for adaptation projects and the potential of subjective assessment approaches for building more ontological and epistemological pluralism in understandings of successful climate change adaptation.  相似文献   
389.
土地质量调查作为地球化学勘查的一种技术手段,具有覆盖面积广、样品类型多等特点。在传统土地质量调查基础上开展绿色勘查具有重要的意义。依据土地质量地球化学调查方法技术体系,提出了土地质量地球化学绿色勘查工作思路,依托胶东典型丘陵区“山东省莱阳北部地区土地质量地球化学调查与评价”项目,系统总结了土地质量地球化学调查中生态环境敏感区识别、点位布设及优化、样品采集及回填、样品加工、采样工具优化等方面的绿色勘查经验和做法,开展了绿色勘查示范,为推广绿色勘查在地球化学勘查工作方面提供了借鉴依据。  相似文献   
390.
地球背景噪声干涉应用研究的新进展   总被引:1,自引:0,他引:1  
对地震台记录到的长时间的地球背景噪声进行互相关处理,得到的互相关函数可以近似地表征这两个台站之间的格林函数,这种数据处理方法被称为背景噪声干涉.近年来,背景噪声干涉研究在理论和实践上都有了长足进展,并被广泛用于地下波速结构及其演化规律的研究.本文首先简单介绍了背景噪声干涉研究的概念和理论依据,进而重点介绍了针对噪声源性质、互相关函数的波形到时和振幅特性的应用研究.通过对这三个方面研究的回顾,分析总结了该研究领域的新进展及需要解决的问题,并对背景噪声干涉研究的新特点进行了分析和展望.  相似文献   
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