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141.
For (134/137)Cs, and many other soil contaminants, research into transfer to plants has focused on particular crops and phytoremediation candidates, producing uptake data for a small proportion of all plant taxa. Despite the significance of differences in uptake between plant taxa, the capacity of soil-to-plant transfer models to predict them is currently confined to those taxa for which data exist, there being no method to predict uptake by other taxa. We used residual maximum likelihood (REML) analysis on data from experiments (including 89 plant taxa from China plus 32 phytoremediation candidates) together with data from the literature, to construct a database of relative (134/137)Cs concentrations in 273 plant taxa. The REML (134/137)Cs concentrations in plants are not normally distributed but significantly clustered. Analysis of variance (ANOVA), coded with a recent ordinal phylogeny for flowering plants, showed that plant taxa do not behave independently for (134/137)Cs concentration because 42 and 15% of inter-taxa differences are associated with phylogeny above the species and ordinal level, respectively. In general, Eudicots, and especially the Caryophyllales, Asterales, and Brassicales, have high (134/137)Cs concentrations, while the Fabales and Magnoliids, in particular Poales, have low (134/137)Cs concentrations. Plants of the stress-tolerant ruderal (S-R) growth strategy sensu Grime have, in general, high concentrations of Cs, while those of the competitive (C) and generalist (C-S-R) strategies have low concentrations, although these effects are less pronounced than those of phylogeny. Plant phylogeny and growth strategy might thus be used to predict a significant portion of inter-taxa differences in plant uptake of (134/137)Cs. 相似文献
142.
143.
Kang Huang He Zhang Chengliang Wang Rong Hou Pei Zhang Gang He Songtao Guo Shiyi Tang Baoguo Li Charles Oxnard Ruliang Pan 《Conservation biology》2021,35(6):1787-1796
A systematic understanding of dynamic animal extinction trajectories for different regions in a nation like China is critically important to developing practical conservation strategies. We explored historical and contemporary changes in terrestrial mammalian diversity to determine how diversity in each of the 5 regions in China has changed over time and to examine the conservation potential of these regions. We used records from databases on Pleistocene mammalian fossils and historical distribution records (1175–2020) for Primates (as a case study) to reconstruct evolutionary and historical distribution trajectories of the 11 orders of terrestrial mammals and to predict their prospective survival based on the national conservation strategy applied. The results indicated that since the Pleistocene, 4–5 mammalian orders have been lost in the northeast, 3 in central China, 2 along the coast, and 1 in the northwest. In the southwest, all 11 orders were maintained. Contemporarily, the coast and southwest had the highest and second-highest species densities. The southwest region and southeastern sections of the northwest region were the most historically and contemporarily diverse areas, which suggests that they should be the first priority for protected area (PA) designation. The central and coastal areas should be secondarily prioritized. In these 2 regions, conservation should focus on human coexistence with nature. Less attention should be paid to the PA in the northeast and western northwest because in these areas ecosystems are depauperate and the climate is harsh. Conservation in these areas should focus principally on avoiding further human encroachment on natural areas. Article impact statement: Historical and contemporary patterns of extinction can be a basis for mammalian conservation strategies. 相似文献
144.
Environmental Fluid Mechanics - A hydraulic jump forming in the stilling basin at the base of a high-head dam spillway is often characterized by high Froude number and inflow pre-aeration... 相似文献
145.
三线、对数周期等大尺寸天线大量应用于通信台站与舰船上,然而,考虑到天线放置地点、工作频段、通信覆盖范围等要求,这类天线都具有较大的物理尺寸,在实验室环境和外场试验环境下都无法直接测量辐射方向图、发射效率、驻波比等天线性能指标。以大尺寸短波发射天线现场测试技术为研究对象,分析了大尺寸短波发射天线现场测手段的必要性与所存在的不足,在传统现场测试方法的基础上,提出了一种基于无人机的短波发射天线现场测试方法,对信台站与舰艇上大尺寸短波发射天线的设计、施工、调试、维修、以及现场系统联调等环节起到保障作用。 相似文献
146.
Study on phosphorus loadings in ten natural and agricultural watersheds in subtropical region of China 总被引:3,自引:0,他引:3
Yuyuan Li Cen Meng Ru Gao Wen Yang Junxia Jiao Yong Li Yi Wang Jinshui Wu 《Environmental monitoring and assessment》2014,186(5):2717-2727
Water eutrophication in subtropical regions of southern China threatens watershed health and is of major concern. However, annual phosphorus (P) loading and its dominant causes are still unclear, especially at the watershed scale. In this study, we investigated dynamic P loadings and associated factors (e.g., land use, livestock production, and runoff depth) in ten watersheds that varied in area from 9 to 5,212 ha in a hilly area of Hunan Province, China. A flowmeter was installed at the outlet of each watershed, and total P (TP) and soluble P (SP) concentrations were monitored periodically from June 2010 to October 2012. The results showed that annual P loadings (APLs) in the ten watersheds ranged from 22.8 to 247.8 kg P/km2 and that P loss primarily occurred from April to June of each year during the main rainfall season in the study area. In addition, the average eutrophication (>0.05 mg P/L) ratio for stream waters was 86.7 % during the study period, which was indicative of a potentially serious condition for the local water environments. Annual P loadings were linearly related to livestock density (LD; R?=?0.92, p?<?0.01), whereas the eutrophication ratio of stream water was significantly (p?<?0.05) correlated with LD (R?=?0.61), percentage cropland (R?=?0.71), and percentage forest cover (R?=??0.68). Thus, it is concluded that the control of livestock production has the greatest potential for reducing P loadings in watersheds in this subtropical area. This will be beneficial to the amelioration and protection of local environment. 相似文献
147.
高层建筑竖井火灾中影响因素众多,并且各因素对高层楼梯井火灾中重要现象、关键数值等的影响大小不一,使得此类火灾中的实验或理论研究成本较高。通过建立全局敏感性分析平台,定量考察了高层楼梯井结构所涉及因素的影响大小,并能够方便地筛选掉对所考察量影响较小的因素,以降低实验或计算成本。使用数值模拟方法,通过CFD软件对包含阶梯几何框架的高层楼梯井结构火灾进行了共计60次工况计算。并且根据计算结果,使用全局参数敏感性分析方法,得出建筑尺寸、热释放速率、环境参数对高层楼梯井内烟气湍流特性及输运特性的敏感性排序。结果表明,火源热释放速率对各输出参数的影响均占38%以上。 相似文献
148.
Hu Xiaobing Wang Kun Chang Jing Zhang Lin Zhong Meiying Nie Yong 《Environmental science and pollution research international》2021,28(14):17084-17097
Environmental Science and Pollution Research - Microfaunal identification and analysis are very complex; thus, an image analysis method was utilized in this paper to overcome the shortcomings of... 相似文献
149.
Tang Chengli Xu Di Chen Nicheng 《Environmental science and pollution research international》2021,28(5):5548-5565
Environmental Science and Pollution Research - This work proposed a novel mathematical framework for the sustainability assessment of sewage sludge to energy (SStE) scenarios, by resorting to fuzzy... 相似文献
150.
Tang Kai Liu Yichun Zhou Di Qiu Yuan 《Environmental science and pollution research international》2021,28(5):5168-5179
Environmental Science and Pollution Research - The international community has generally recognized the key role of developing countries’ cities in reducing carbon emissions, an elemental way... 相似文献