Stabilization of Cd-, Pb-, Cu- and Zn-contaminated calcareous agricultural soil using red mud: a field experiment

Red mud (RM) was used to remediate heavy metal-contaminated soils. Experiments with two different dosages of RM added to soils were carried out in this study. It was found that soil pH increased 0.3 and 0.5 unit with the dosage of 3 and 5% (wt%), respectively. At the dosage of 5%, the highest stabilization efficiencies for Cd, Pb, Cu and Zn reached 67.95, 64.21, 43.73 and 63.73%, respectively. The addition of RM obviously transferred Cd from the exchangeable fraction to the residual fraction. Meanwhile, in comparison with the control (no RM added), it reduced 24.38, 49.20, 19.42 and 8.89% of Cd, Pb, Cu and Zn in wheat grains at the RM addition dosage of 5%, respectively. At the same time, the yield of wheat grains increased 17.81 and 24.66% at the RM addition dosage of 3 and 5%, respectively. Finally, the addition of RM did not change the soil bacterial community. These results indicate that RM has a great potential in stabilizing heavy metals in calcareous agricultural soils.

     

氟离子慢性暴露对中国林蛙蝌蚪生长发育的毒性效应研究

氟元素以不同的结合形式广泛存在于自然界中,适量氟的摄取有益于龋齿预防和骨骼发育,然而过量氟的摄取会对动物及人体健康造成危害。近年来,大量的人类活动导致水环境中氟含量持续升高。为探究水域氟污染对中国林蛙的毒性影响,本研究以中国林蛙(Rana chensinensis)胚胎为试验材料,对卵黄栓期(G12期)胚胎进行了0、0.7、4.2、19.4、42.8 mg·L~(-1)F-慢性水体暴露直至胚胎发育到变态高峰期(G42期)的研究。分别于暴露25 d和40 d后取样测定了蝌蚪全长、体长、体重和发育分期;此外,分析了F-慢性暴露对变态率、G42期蝌蚪的全长、体长、体重和后肢长以及G42期蝌蚪骨骼发育的影响。结果表明:暴露25 d时,4.2 mg·L~(-1)F-处理组促进了林蛙蝌蚪的生长发育,而42.8 mg·L~(-1)F-处理组显著抑制了蝌蚪的生长发育;暴露40 d时,19.4 mg·L~(-1)F-和42.8 mg·L~(-1)F-处理组蝌蚪的生长发育均受到显著抑制。持续进行慢性暴露78 d后,4.2 mg·L~(-1)F-处理组蝌蚪的变态率显著升高,而42.8 mg·L~(-1)F-处理组蝌蚪的变态率受到了显著抑制。此外,42.8 mg·L~(-1)F-处理组G42期蝌蚪形态指标(全长、体长和后肢长)以及骨骼发育均受到抑制。依据G42期中国林蛙蝌蚪的生长发育指标和变态率为观察指标,氟离子慢性暴露对中国林蛙蝌蚪的最低可观察效应浓度(LOEC)为0.7 mg·L~(-1)。研究表明,水环境中高浓度的氟污染会对中国林蛙蝌蚪的生长发育、变态和骨骼发育等造成潜在的不利影响,水体氟污染的生态毒性效应理应引起高度重视。     

绿色建筑小区雨水资源化综合利用技术

运用生态学原理设计绿色建筑小区已逐渐成为潮流,节水与水资源利用的问题正日益受到关注。绿色建筑小区雨水资源化综合利用技术集成优化了小区雨水收集与分散处理系统、雨水集中收集与处理系统、雨水渗透系统等技术,具有投资省、处理效果好、管理方便等优点,适合为今后的绿色建筑小区雨水资源化综合利用建设参考。     

Role of winter temperature and climate change on the survival and future range expansion of the hemlock woolly adelgid (Adelges tsugae) in eastern North America

Global climate change has already affected the abundances, range limits, and interactions of many species. The hemlock woolly adelgid (Adelges tsugae), an invasive insect introduced to eastern North America from Japan, has decimated stands of eastern hemlock (Tsuga canadensis) and Carolina hemlock (T. caroliniana) from Georgia to Connecticut. However, its spread across central and northern New England has been slowed substantially by its inability to tolerate cold winter temperatures. Using data from previous lab and field studies collected over the past 17 years, including adelgid spread and overwintering mortality, we first characterize the temperature conditions that may limit adelgid spread. We then show how, in the future, rising winter temperatures due to climate change are likely to remove the conditions currently limiting adelgid spread, and facilitate the northward expansion as more suitable habitat becomes available.     

佳木斯市粉煤灰资源综合利用可行性分析

通过分析佳木斯市粉煤灰的产生量和主要用途,探讨粉煤灰综合利用的方法及原理,从而解决佳木斯市粉煤灰对环境的影响,变废为宝,实现固体废弃物的减量化、资源化、无害化.目的是解决建筑的填埋造成土地的不可复耕,破坏生态和粉煤灰的填埋产生的渗滤液对地下水的威胁.使固体废物综合利用项目可以收到良好的社会效益、经济效益、环境效益,阐述在佳木斯市投资粉煤灰综合利用项目的的可行性.     

Spatial-temporal analysis of wetland landscape pattern under the influence of artificial dykes in the Yellow River delta

The influence of anthropogenic activities,especially artificial dykes,on the coastal wetland landscape is now considered as a serious problem to the coastal ecosystem.It is important and necessary to analyze changes of coastal landscape pattern under the influence of artificial dykes for the protection and management of coastal wetland.Our study aimed to reveal the quantitative characteristics of the coastal wetland landscape and its spatial-temporal dynamics under the influence of artificial dykes in the Yellow River delta(YRD).It was analyzed by the methods of the statistical analysis of landscape structure,five selected landscape indices and the changes of spatial centroids of three typical wetland types,including reed marshes,tidal fiats and aquaculture-salt fields.The results showed that:(1)Reduction of wetland area,especially the degradation of natural wetlands,had been the principal problem since the dykes were constructed in the YRD.The dykes created conditions for the development of artificial wetlands.However,the new born artificial wetlands were still less than the vanished natural wetlands.(2)Compared with the open area,the building of artificial dykes significantly speeded up the changes of landscape patterns and the aggravation of the landscape fragmentation in the closed area.(3)The changes of area-weighted centroids of three typical wetland landscapes were greatly affected by dykes,and the movement of the centroid of the aquaculture-salt field was very sensitive to the dykes constructed in the corresponding period.     

Research on Tourism Competitiveness of Chinese Island Counties: Based on Factor and Cluster Analysis

Abstract

From the perspective of tourism competitiveness, the paper takes 12 island counties of China as the research object, and applies the method of factor analysis to study their competitiveness. The result shows that Putuo and Dinghai are more competitive while Pingtan and Nan’ao are less competitive. Finally, the 12 island counties are divided into four styles: first-class competitive county (Putuo), seond-class competitive counties (Dinghai,Yuhuan), third-class competitive counties (Chongming, Daishan, Changdao, Changhai and Shengsi), fourth-class competitive counties (Dongshan, Dongtou, Pingtan and Nan’ao) by cluster analysis. The classification of island counties is to clear their relative position, then to promote their development.     

X-ray microspectroscopy and chemical reactions in soil microsites

Soils provide long-term storage of environmental contaminants, which helps to protect water and air quality and diminishes negative impacts of contaminants on human and ecosystem health. Characterizing solid-phase chemical species in highly complex matrices is essential for developing principles that can be broadly applied to the wide range of notoriously heterogeneous soils occurring at the earth's surface. In the context of historical developments in soil analytical techniques, we describe applications of bulk-sample and spatially resolved synchrotron X-ray absorption spectroscopy (XAS) for characterizing chemical species of contaminants in soils, and for determining the uniqueness of trace-element reactivity in different soil microsites. Spatially resolved X-ray techniques provide opportunities for following chemical changes within soil microsites that serve as highly localized chemical micro- (or nano-)reactors of unique composition. An example of this microreactor concept is shown for micro-X-ray absorption near edge structure analysis of metal sulfide oxidation in a contaminated soil. One research challenge is to use information and principles developed from microscale soil chemistry for predicting macroscale and field-scale behavior of soil contaminants.     

Mangrove vulnerability modelling in parts of Western Niger Delta, Nigeria using satellite images, GIS techniques and Spatial Multi-Criteria Analysis (SMCA)

Mangroves are known for their global environmental and socioeconomic value. Despite their importance, mangrove like other ecosystems is now being threatened by natural and human-induced processes that damage them at alarming rates, thereby diminishing the limited number of existing mangrove vegetation. The development of a spatial vulnerability assessment model that takes into consideration environmental and socioeconomic criteria, in spatial and non-spatial formats has been attempted in this study. According to the model, 11 different input parameters are required in modelling mangrove vulnerability. These parameters and their effects on mangrove vulnerability were selected and weighted by experts in the related fields. Criteria identification and selection were mainly based on effects of environmental and socioeconomic changes associated with mangrove survival. The results obtained revealed the dominance of socioeconomic criteria such as population pressure and deforestation, with high vulnerability index of 0.75. The environmental criteria was broadly dispersed in the study area and represents vulnerability indices ranging from 0.00?C0.75. This category reflects the greater influence of pollutant input from oil wells and pipelines and minimal contribution from climatic factors. This project has integrated spatial management framework for mangrove vulnerability assessment that utilises information technology in conjunction with expert knowledge and multi-criteria analysis to aid planners and policy/ decision makers in the protection of this very fragile ecosystem.     

Operators’ signal-detection performance in video display unit monitoring tasks of the main control room

This study evaluated the operators’ signal-detection performance in video display unit (VDU) monitoring tasks of the main control room (MCR). So far the study of the relationship between VDU design strategy and human errors has been superficial. To validate the effect of VDUs design strategies on operating errors in the MCR, this present research adopted a within subject experimental design to develop different experimental treatments based on two types of display modes included consistent mode and mixed mode. A total of 13 undergraduate and graduate students were recruited as participants in the experiment. Dependent variables included situation awareness, reaction time, error frequency, and subjective performance. Some research support was found for the representation principles. The conclusions of this study could not only be implemented by the human-system interface (HSI) designers of a MCR in the advanced nuclear power plant (NPP) but also could be generalized to the extent that other digital workstation similar to the MCR.