100%掺量RAP环氧沥青热再生混合料技术可满足路面旧料循环利用率达到90%以上,在日益重视环境和生态保护的当今社会具有较好的应用前景。但目前配合比设计方面尚无成熟的设计和评价体系,针对其配合比设计进行了探讨,研究了不同保温时间...100%掺量RAP环氧沥青热再生混合料技术可满足路面旧料循环利用率达到90%以上,在日益重视环境和生态保护的当今社会具有较好的应用前景。但目前配合比设计方面尚无成熟的设计和评价体系,针对其配合比设计进行了探讨,研究了不同保温时间对混合料的影响,同时对设计的混合料进行了路用性能研究。试验结果表明:设计的混合料残留稳定度为90.1%,劈裂强度比90.3%,动稳定度为9226次/mm,破坏应变为2750.5με疲劳寿命大于100万次由此可知该混合料在水稳定性、高温稳定性、疲劳方面具有一定的优势,在低温性能方面略有改善。该技术可解决当前R A P掺量偏低问题,具有一定的推广价值。展开更多
The Himalayan Yew (Taxus baccata subsp. wallichiana) is an endangered native high value medicinal plant of the Himalayan Region. The several medicinal properties of the bark and leaves of this species have increased i...The Himalayan Yew (Taxus baccata subsp. wallichiana) is an endangered native high value medicinal plant of the Himalayan Region. The several medicinal properties of the bark and leaves of this species have increased its risk of extinction due to pressures for utilization. It is also subjected to harvest for fuelwood. The species does not regenerate well from seed and that is another risk factor. The objective of this research was to investigate the population ecology of the species as a foundation for its conservation. Six forest communities in the Khokhan Wildlife Sanctuary where the species is present were sampled. The abundance of the species, impacts of harvesting and its current regeneration patterns indicate that it may soon be extirpated from the Sanctuary. A plan for conserving the remaining sub-populations is presented. It could provide a template for conservation in other locations where the species is at risk.展开更多
Method for constructing the optimal water supply line and formulas for calculating the targets for single-contaminant regeneration recycling water systems are improved to apply to the situation of variational pararnet...Method for constructing the optimal water supply line and formulas for calculating the targets for single-contaminant regeneration recycling water systems are improved to apply to the situation of variational pararneters in this article. Based on these extending methods, the effect of varying freshwater consumption and regenerated water flow rate on the optimizing results are investigated. The interactions of parameters of regeneration recycling systems are summarized. Finally, all the conclusions are illustrated from the results of mathematical programming through an example.展开更多
Serious soil erosion has made the eco-environment fragile in the Loess Plateau. Based on the 10-year data observed from 1989 to 1998 in the Ziwuling Survey Station in loess hilly region, the eco-environment change and...Serious soil erosion has made the eco-environment fragile in the Loess Plateau. Based on the 10-year data observed from 1989 to 1998 in the Ziwuling Survey Station in loess hilly region, the eco-environment change and soil erosion process in reclaimed forestland were studied in this paper. The results showed that the intensity of man-made soil erosion caused by forestland reclamation was 1000 times more than that of the natural erosion. From the analysis of soil physical and mechanical properties, in the 10th year after forestland was reclaimed, the clay content and physical clay content decreased 2.74 percentage point and 3.01 percentage point respectively, the >0.25mm waterstable aggregate content decreased 31.59 percentage point, the soil bulk density increased and soil shear strength decreased, all of which were easier to cause soil erosion. The correlation analysis showed that >0.25mm waterstable aggregate content was the key factor affecting soil erosion, and the secondary factors were soil coarse grain and soil shear strength. The relation between the >0.25mm waterstable aggregate content, the soil sheer strength and the soil erosion intensity were analyzed, which showed that the first year and the seventh erosion year were the turn years of the soil erosion intensity after the forestland was reclaimed, revealed that the change of eco-environment was the main cause to accelerate soil erosion, and the worse environment caused soil erosion to be serious rapidly.展开更多
In order to take full advantage of regeneration process to reduce fresh water consumption and avoid the accumulation of trace contaminants, regeneration reuse and regeneration recycle should be distinctive. A stepwise...In order to take full advantage of regeneration process to reduce fresh water consumption and avoid the accumulation of trace contaminants, regeneration reuse and regeneration recycle should be distinctive. A stepwise optimal design for water network is developed to simplify solution procedures for the formulated MINLP problem. In this paper, a feasible water reuse network framework is generated. Some heuristic rules from water reuse network are used to guide the placement of regeneration process. Then the outlet stream of regeneration process is considered as new water source. Regeneration reuse network structure is obtained through an iterative optimal procedure by taking the insights from reuse water network structure. Furthermore, regeneration recycle is only utilized to eliminate fresh water usage for processes in which regeneration reuse is impossible. Compared with the results obtained by relevant researches for the same example, the present method not only provides an appropriate regeneration reuse water network with minimum fresh water and regenerated water flow rate but also suggests a water network involving regeneration recycle with minimum recycle water flow rate. The design can utilize reuse, regeneration reuse and regeneration recycle step by step with minor water network structure change to achieve better flexibility. It can satisfy different demands for new plants and modernization of existing plants.展开更多
文摘100%掺量RAP环氧沥青热再生混合料技术可满足路面旧料循环利用率达到90%以上,在日益重视环境和生态保护的当今社会具有较好的应用前景。但目前配合比设计方面尚无成熟的设计和评价体系,针对其配合比设计进行了探讨,研究了不同保温时间对混合料的影响,同时对设计的混合料进行了路用性能研究。试验结果表明:设计的混合料残留稳定度为90.1%,劈裂强度比90.3%,动稳定度为9226次/mm,破坏应变为2750.5με疲劳寿命大于100万次由此可知该混合料在水稳定性、高温稳定性、疲劳方面具有一定的优势,在低温性能方面略有改善。该技术可解决当前R A P掺量偏低问题,具有一定的推广价值。
文摘The Himalayan Yew (Taxus baccata subsp. wallichiana) is an endangered native high value medicinal plant of the Himalayan Region. The several medicinal properties of the bark and leaves of this species have increased its risk of extinction due to pressures for utilization. It is also subjected to harvest for fuelwood. The species does not regenerate well from seed and that is another risk factor. The objective of this research was to investigate the population ecology of the species as a foundation for its conservation. Six forest communities in the Khokhan Wildlife Sanctuary where the species is present were sampled. The abundance of the species, impacts of harvesting and its current regeneration patterns indicate that it may soon be extirpated from the Sanctuary. A plan for conserving the remaining sub-populations is presented. It could provide a template for conservation in other locations where the species is at risk.
基金Supported by the National Natural Science Foundation of China （No.20436040）.
文摘Method for constructing the optimal water supply line and formulas for calculating the targets for single-contaminant regeneration recycling water systems are improved to apply to the situation of variational pararneters in this article. Based on these extending methods, the effect of varying freshwater consumption and regenerated water flow rate on the optimizing results are investigated. The interactions of parameters of regeneration recycling systems are summarized. Finally, all the conclusions are illustrated from the results of mathematical programming through an example.
文摘Serious soil erosion has made the eco-environment fragile in the Loess Plateau. Based on the 10-year data observed from 1989 to 1998 in the Ziwuling Survey Station in loess hilly region, the eco-environment change and soil erosion process in reclaimed forestland were studied in this paper. The results showed that the intensity of man-made soil erosion caused by forestland reclamation was 1000 times more than that of the natural erosion. From the analysis of soil physical and mechanical properties, in the 10th year after forestland was reclaimed, the clay content and physical clay content decreased 2.74 percentage point and 3.01 percentage point respectively, the >0.25mm waterstable aggregate content decreased 31.59 percentage point, the soil bulk density increased and soil shear strength decreased, all of which were easier to cause soil erosion. The correlation analysis showed that >0.25mm waterstable aggregate content was the key factor affecting soil erosion, and the secondary factors were soil coarse grain and soil shear strength. The relation between the >0.25mm waterstable aggregate content, the soil sheer strength and the soil erosion intensity were analyzed, which showed that the first year and the seventh erosion year were the turn years of the soil erosion intensity after the forestland was reclaimed, revealed that the change of eco-environment was the main cause to accelerate soil erosion, and the worse environment caused soil erosion to be serious rapidly.
基金Supported by the National Natural Science Foundation of China(20906007)
文摘In order to take full advantage of regeneration process to reduce fresh water consumption and avoid the accumulation of trace contaminants, regeneration reuse and regeneration recycle should be distinctive. A stepwise optimal design for water network is developed to simplify solution procedures for the formulated MINLP problem. In this paper, a feasible water reuse network framework is generated. Some heuristic rules from water reuse network are used to guide the placement of regeneration process. Then the outlet stream of regeneration process is considered as new water source. Regeneration reuse network structure is obtained through an iterative optimal procedure by taking the insights from reuse water network structure. Furthermore, regeneration recycle is only utilized to eliminate fresh water usage for processes in which regeneration reuse is impossible. Compared with the results obtained by relevant researches for the same example, the present method not only provides an appropriate regeneration reuse water network with minimum fresh water and regenerated water flow rate but also suggests a water network involving regeneration recycle with minimum recycle water flow rate. The design can utilize reuse, regeneration reuse and regeneration recycle step by step with minor water network structure change to achieve better flexibility. It can satisfy different demands for new plants and modernization of existing plants.
