[Objective] This study aimed to understand and grasp the soil heavy metal pollution status of agricultural habitat environment in Xi＇an City. [Method] The soil heavy metal pollution status of pollution-free agricultu...[Objective] This study aimed to understand and grasp the soil heavy metal pollution status of agricultural habitat environment in Xi＇an City. [Method] The soil heavy metal pollution status of pollution-free agricultural products-producing areas in 9 counties （districts） of Xi＇an City was investigated. A total of 609 soil samples were collected, and their Cd, Hg, As, Pb and Cr contents were determined. In addition, the heavy metal pollution status of the collected soil samples was evaluated by Nemerow index method. [Result] The pollution in Baqiao, Chang＇an; Gaoling, Lan- tian, Lintong and Yanliang was of grade I, belonging to clean level; the pollution in Hu County, Weiyang and Zhouzhi was of grade II, near the warning line, belong to relatively clean level. There was no large-area soil heavy metal pollution overall. The investigated areas could be used as production bases of pollution-free agricultural products and even high-quality agricultural products. However, the heavy met- als contents in some individual areas exceeded relevant soil environmental quality standards, and they should be avoided or forbidden during regional planning and selection of production area. [Conclusion] Soil heavy metal pollution of agricultural habitat environment in Xi＇an City is generally at good status. Targeting at the future development plan of Xi＇an City, feasible and scientific suggestions are put forward.展开更多
The growth of regional economy in China was stable with a slight decline in2013.Growths in major economic indicators,namely the industrial added value,the total fixed asset investment,the total retail sales of consume...The growth of regional economy in China was stable with a slight decline in2013.Growths in major economic indicators,namely the industrial added value,the total fixed asset investment,the total retail sales of consumer goods,and the total volume of import and export trade differ across the eastern,central,western and northeastern regions,but the overall difference is small.The regional economic development still faces certain problems,such as unbalanced development among regions,insufficient implementation of development planning,lack of in-depth regional cooperation,irrational competition of development of new zones,and uncoordinated policies on ecological progress from different government authorities.This paper suggests that China should formulate zoning policies and supporting measures to accelerate the development of key economic belts,promote new urbanization,transform the old industrial bases,strengthen joint prevention of regional environmental pollution and promote the opening up of the inland areas to the western regions.展开更多
In this paper we analyze the characteristics of the so-called rare earth elements （REEs） and its industrial applications. We present the policy, or lack thereof, in the countries in the Pacific Rim for its mining an...In this paper we analyze the characteristics of the so-called rare earth elements （REEs） and its industrial applications. We present the policy, or lack thereof, in the countries in the Pacific Rim for its mining and commerce, and the current and future weight that rare earth minerals will have in international trade. The technological revolution experienced over the last 25 years, has brought the REEs to the public＇s attention for being instrumental in obtaining catalysts, lasers and optical fiber, luminescent substances and LEDs, superconductors, permanent magnets, batteries and ultra-capacitors. China＇s leading position as the supplier of these minerals worldwide, and its recent export restriction policy for domestic industrial activities have driven up international prices. Price increase for REEs is leading to the need for both recycling and its replacement. It has also led other countries in the Asia Pacific Rim to prospect new potential sites on their own territories, or even to restart operations in deposits that had been previously abandoned. Those strategies will likely gain greater importance as environmental pollution problems associated with the exploitation, processing, and recovery of REEs increase.展开更多
文摘[Objective] This study aimed to understand and grasp the soil heavy metal pollution status of agricultural habitat environment in Xi＇an City. [Method] The soil heavy metal pollution status of pollution-free agricultural products-producing areas in 9 counties （districts） of Xi＇an City was investigated. A total of 609 soil samples were collected, and their Cd, Hg, As, Pb and Cr contents were determined. In addition, the heavy metal pollution status of the collected soil samples was evaluated by Nemerow index method. [Result] The pollution in Baqiao, Chang＇an; Gaoling, Lan- tian, Lintong and Yanliang was of grade I, belonging to clean level; the pollution in Hu County, Weiyang and Zhouzhi was of grade II, near the warning line, belong to relatively clean level. There was no large-area soil heavy metal pollution overall. The investigated areas could be used as production bases of pollution-free agricultural products and even high-quality agricultural products. However, the heavy met- als contents in some individual areas exceeded relevant soil environmental quality standards, and they should be avoided or forbidden during regional planning and selection of production area. [Conclusion] Soil heavy metal pollution of agricultural habitat environment in Xi＇an City is generally at good status. Targeting at the future development plan of Xi＇an City, feasible and scientific suggestions are put forward.
文摘The growth of regional economy in China was stable with a slight decline in2013.Growths in major economic indicators,namely the industrial added value,the total fixed asset investment,the total retail sales of consumer goods,and the total volume of import and export trade differ across the eastern,central,western and northeastern regions,but the overall difference is small.The regional economic development still faces certain problems,such as unbalanced development among regions,insufficient implementation of development planning,lack of in-depth regional cooperation,irrational competition of development of new zones,and uncoordinated policies on ecological progress from different government authorities.This paper suggests that China should formulate zoning policies and supporting measures to accelerate the development of key economic belts,promote new urbanization,transform the old industrial bases,strengthen joint prevention of regional environmental pollution and promote the opening up of the inland areas to the western regions.
文摘In this paper we analyze the characteristics of the so-called rare earth elements （REEs） and its industrial applications. We present the policy, or lack thereof, in the countries in the Pacific Rim for its mining and commerce, and the current and future weight that rare earth minerals will have in international trade. The technological revolution experienced over the last 25 years, has brought the REEs to the public＇s attention for being instrumental in obtaining catalysts, lasers and optical fiber, luminescent substances and LEDs, superconductors, permanent magnets, batteries and ultra-capacitors. China＇s leading position as the supplier of these minerals worldwide, and its recent export restriction policy for domestic industrial activities have driven up international prices. Price increase for REEs is leading to the need for both recycling and its replacement. It has also led other countries in the Asia Pacific Rim to prospect new potential sites on their own territories, or even to restart operations in deposits that had been previously abandoned. Those strategies will likely gain greater importance as environmental pollution problems associated with the exploitation, processing, and recovery of REEs increase.
