Quaternary aeolian environment researches were mainly conducted by analyzing the information carriers, extracting valuable evidences about aeolian environment changes, so to presume and reconstruct paleoenvironments. ...Quaternary aeolian environment researches were mainly conducted by analyzing the information carriers, extracting valuable evidences about aeolian environment changes, so to presume and reconstruct paleoenvironments. This paper formulated progress in Quaternary aeolian environment research using dune-morphological records, sedimentological records and bio-fossils records, as well as advances about chronology; presented that people should pay more attention to further synthetic study of multi-types of records including dune morphology, size, formation time, sediment supply, and their relations with wind regime in future, especially the research on dating method.展开更多
The Sakaerat Environmental Research Station （SERS） was established to promote long-term ecological research （LTER） and to demonstrate sustainable forest management and biodiversity conservation. In the past decade...The Sakaerat Environmental Research Station （SERS） was established to promote long-term ecological research （LTER） and to demonstrate sustainable forest management and biodiversity conservation. In the past decade, the government has put a lot of effort into rehabilitating degraded forest both inside and surrounding the SERS landscape in order to link fragmented forest patches. However, there is a lack of appropriate methods that allow the measurement of the effectiveness of reforestation. The objective of this paper is to quantify land use and landscape structure changes between 1990 and 2002. The study area encompasses the SERS and its buffer zone. Land use/land cover maps were visually interpreted into 9 classes using temporal Landsat-TM images. These classes were dry evergreen forest, mixed deciduous forest, dry dipterocarp forest, secondary growth, plantation, grassland, old clearing, agriculture ＆ settlement, and water body. In addition, a Geographic Information System （GIS） and FRAGSTATS package were used to assess fragmentation indices. The results revealed that the annual increment rate of dry evergreen forest and dry dipterocarp forest were 0.51% and 0.97%, respectively. In addition, the total area of forest plantation expanded to roughly three times or increased 193.23% during this period. Agricultural and settlement area decreased 7.56% per year. Most of this area was replaced by plantation and natural regeneration. The fragmentation indices indicated that the remaining dry evergreen forest was highly aggregated or had low fragmentation. The number of patches decreased from 7 to 5, and mean patch size increased significantly. However, mixed deciduous forest and dry dipterocarp forest were relatively fragmented. Mixed deciduous forest showed higher fragmentation. Mean patch size area was substantially decreased from 293 ha in 1990 to 123 ha in 2002 and the mean nearest neighbor distance increased by approximately 400 m during this period.展开更多
Leaching is an important way of precipitation of trace elements. It is known from the leaching experiment that the content of trace elements precipitated from coal or waste is related to their existing status and conc...Leaching is an important way of precipitation of trace elements. It is known from the leaching experiment that the content of trace elements precipitated from coal or waste is related to their existing status and concentration in coal, it is also affected by time of leaching, temperature of leaching-liquid and its pH value. The higher temperature of leaching-liquid and the longer of leaching are, the higher precipitation conceatration of trace elements will be. In the course of leaching, pH value of leaching-liquid changes, and the different trace elements are differently effected by pH value.展开更多
基金Undertheauspicesof the National Natural Science Foundation of China (No. 40271114, 40471013)
文摘Quaternary aeolian environment researches were mainly conducted by analyzing the information carriers, extracting valuable evidences about aeolian environment changes, so to presume and reconstruct paleoenvironments. This paper formulated progress in Quaternary aeolian environment research using dune-morphological records, sedimentological records and bio-fossils records, as well as advances about chronology; presented that people should pay more attention to further synthetic study of multi-types of records including dune morphology, size, formation time, sediment supply, and their relations with wind regime in future, especially the research on dating method.
文摘The Sakaerat Environmental Research Station （SERS） was established to promote long-term ecological research （LTER） and to demonstrate sustainable forest management and biodiversity conservation. In the past decade, the government has put a lot of effort into rehabilitating degraded forest both inside and surrounding the SERS landscape in order to link fragmented forest patches. However, there is a lack of appropriate methods that allow the measurement of the effectiveness of reforestation. The objective of this paper is to quantify land use and landscape structure changes between 1990 and 2002. The study area encompasses the SERS and its buffer zone. Land use/land cover maps were visually interpreted into 9 classes using temporal Landsat-TM images. These classes were dry evergreen forest, mixed deciduous forest, dry dipterocarp forest, secondary growth, plantation, grassland, old clearing, agriculture ＆ settlement, and water body. In addition, a Geographic Information System （GIS） and FRAGSTATS package were used to assess fragmentation indices. The results revealed that the annual increment rate of dry evergreen forest and dry dipterocarp forest were 0.51% and 0.97%, respectively. In addition, the total area of forest plantation expanded to roughly three times or increased 193.23% during this period. Agricultural and settlement area decreased 7.56% per year. Most of this area was replaced by plantation and natural regeneration. The fragmentation indices indicated that the remaining dry evergreen forest was highly aggregated or had low fragmentation. The number of patches decreased from 7 to 5, and mean patch size increased significantly. However, mixed deciduous forest and dry dipterocarp forest were relatively fragmented. Mixed deciduous forest showed higher fragmentation. Mean patch size area was substantially decreased from 293 ha in 1990 to 123 ha in 2002 and the mean nearest neighbor distance increased by approximately 400 m during this period.
文摘Leaching is an important way of precipitation of trace elements. It is known from the leaching experiment that the content of trace elements precipitated from coal or waste is related to their existing status and concentration in coal, it is also affected by time of leaching, temperature of leaching-liquid and its pH value. The higher temperature of leaching-liquid and the longer of leaching are, the higher precipitation conceatration of trace elements will be. In the course of leaching, pH value of leaching-liquid changes, and the different trace elements are differently effected by pH value.
