Traditionally,Ag-containing solid wastes are leached by nitric acid in order to recycle the noble metal.However,the huge amounts of emission of toxic nitrogen oxides demand the development of a new method for silver r...Traditionally,Ag-containing solid wastes are leached by nitric acid in order to recycle the noble metal.However,the huge amounts of emission of toxic nitrogen oxides demand the development of a new method for silver recycling.Recently,considering the Ce(Ⅳ)solution could be regenerated with electrolyzation method,our group invented a novel environmentally friendly process by using Ce(Ⅳ)as the oxidant to dissolve silver from the spent Ag/ɑ-Al_2O_3 catalysts without NO_x emission.To find out the optimal parameters,in this work,the leaching reaction was thoroughly investigated with respect to the temperature,oxidant and HNO_3 concentrations,stirring speed,and time.The optimized leaching reaction gave the leaching silver rate 99.8% in 1 h.The kinetic plots suggested a shrinking core model with the internal diffusion-controlled process and the activation energy of 38.83 k J·mol^(-1).The order in which the experimental conditions influence the reaction was determined through orthogonal analysis:temperature N oxidant concentration N HNO_3 concentration N stirring speed.展开更多
Biomineralization of Si by plants into phytolith formation and precipitation of Si into clays during weathering are two important processes of silicon’s biogeochemical cycle. As a silicon-accumulating plant, the wide...Biomineralization of Si by plants into phytolith formation and precipitation of Si into clays during weathering are two important processes of silicon’s biogeochemical cycle. As a silicon-accumulating plant, the widely distributed and woody Phyl-lostachys heterocycla var. pubescens (moso bamboo) contributes to storing silicon by biomineralization and, thus, prevents eu-trophication of nearby waterbodies through silicon’s erosion of soil particles. A study on the organic pool and biological cycle of silicon (Si) of the moso bamboo community was conducted in Wuyishan Biosphere Reserve, China. The results showed that: (1) the standing crop of the moso bamboo community was 13355.4 g/m2, of which 53.61%, 45.82% and 0.56% are represented by the aboveground and belowground parts of moso bamboos, and the under-story plants, respectively; (2) the annual net primary production of the community was 2887.1 g/(m2·a), among which the aboveground part, belowground part, litterfalls, and other fractions, accounted for 55.86%, 35.30%, 4.50% and 4.34%, respec-tively; (3) silicon concentration in stem, branch, leaf, base of stem, root, whip of bamboos, and other plants was 0.15%, 0.79%, 3.10%, 4.40%, 7.32%, 1.52% and 1.01%, respectively; (4) the total Si accumulated in the standing crop of moso bamboo com-munity was 448.91 g/m2, with 99.83% of Si of the total community stored in moso bamboo populations; (5) within moso bamboo community, the annual uptake, retention, and return of Si were 95.75, 68.43, 27.32 g/(m2·a), respectively; (6) the turnover time of Si, which is the time an average atom of Si remains in the soil before it is recycled into the trees or shrubs, was 16.4 years; (7) the enrichment ratio of Si in the moso bamboo community, which is the ratio of the mean concentration of nutrients in the net primary production to the mean concentration of nutrients in the biomass of a community, was 0.64; and lastly, (8) moso bamboo plants stored about 1.26×1010 kg of silicon in the organic pool made up by the moso bamboo forests in the subtropical area of China.展开更多
Fire is quite a common natural phenomenon closely related to forest hydrology in forest ecosystem. The influence of fire on water is indirectly manifested in that the post fire changes of vegetation, ground cover, soi...Fire is quite a common natural phenomenon closely related to forest hydrology in forest ecosystem. The influence of fire on water is indirectly manifested in that the post fire changes of vegetation, ground cover, soil and environment affect water cycle, water quality and aquatic lives. The effect varies depending upon fire severity and frequency. Light wildland fires or prescribed burnings do not affect hydrology regime significantly but frequent burnings or intense fires can cause changes in hydrology regime similar to that caused clear cutting.展开更多
Global water security is a severe issue that threatens human health and well-being. Finding sustainable alternative water resources has become a matter of great urgency. For coastal urban areas, desalinated seawater c...Global water security is a severe issue that threatens human health and well-being. Finding sustainable alternative water resources has become a matter of great urgency. For coastal urban areas, desalinated seawater could serve as a freshwater supply. However, since 20%-30% of the water supply is used for flushing waste from the city, seawater with simple treatment could also partly replace the use of freshwater. In this work, the freshwater saving potential and environmental impacts of the urban water system (water-wastewater closed loop) adopting seawater desalination, seawater for toilet flushing (SWTF), or reclaimed water for toilet flushing (RWTF) are compared with those of a conventional freshwater system, through a life-cycle assessment and sensitivity analysis. The potential applications of these processes are also assessed. The results support the environmental sustainability of the SWTF approach, but its potential application depends on the coastal distance and effective population density of a city. Developed coastal cities with an effective population density exceeding 3000 persons.km-2 and located less than 30 km from the seashore (for the main pipe supplying seawater to the city) would benefit from applying SWTF, regardless of other impact parameters. By further applying the sulfate reduction, autotrophic denitrification, and nitrification integrated (SANI) process for wastewater treatment, the maximum distance from the seashore can be extended to 60 km. Considering that most modern urbanized cities fulfill these criteria, the next generation of water supply systems could consist of a freshwater supply coupled with a seawater supply for sustainable urban development.展开更多
The crushing performance of printed circuit board (PCB) was studied on several crushers. The results show that PCB is a material which is difficult to crush. The crushing performance of PCB with disk crusher, especial...The crushing performance of printed circuit board (PCB) was studied on several crushers. The results show that PCB is a material which is difficult to crush. The crushing performance of PCB with disk crusher, especially vibration grinding, which has cut or impact action, excels that of jaw crusher or roller crusher. The PCB scrap is worthwhile to recycle using variety of modern characterization methods. When compared with natural resources, this material stream remains a rich precious metal and nonferrous metals. In PCB scrap, metals account for 47% of the total material composition, in which there exists 19.66% copper, 11.47% iron, 3.93% lead, 300 g/t gold and 510 kg/t silver, etc. In addition, the PCB scrap contains 27% of plastics and 26% of refractory oxides.展开更多
Based on an analysis of our research results and the main problems relating to urban rainwater treatment, we propose a new approach to urban rainwater management in China. The necessity and feasibility of such a new a...Based on an analysis of our research results and the main problems relating to urban rainwater treatment, we propose a new approach to urban rainwater management in China. The necessity and feasibility of such a new approach are discussed. From an ecological point of view all components of the global system, including residents living in cities, have the same right to enjoy rainwater. Therefore, urban rainwater should neither be simply drained as waste water, nor be completely harvested as a kind of resource. The objective of this new approach is to maintain the natural hydrological cycle in urban areas during urbanization. When necessary, it could also be used to regulate the amount of runoff, evaporation and infiltration in a city in order to rehabilitate the hydrological cycle given the local conditions. Three basic principles should be adopted in rainwater management, i.e., separation of rainfall from sewage, limited utilization and small and decentralized facilities. Four methods can be used for urban rainwater management: rainwater harvest, rainwater infiltration, rainwater storage and rainwater pipes. The natural hydrological cycle in urban areas could be rehabilitated through rainwater management, which is of great importance for sustainable development of our cities.展开更多
Ecological footprint (EF) has received considerable attention as a useful indicator in the context of sustainable development. So far, EF has been used in numerous studies by academies, organizations and government au...Ecological footprint (EF) has received considerable attention as a useful indicator in the context of sustainable development. So far, EF has been used in numerous studies by academies, organizations and government authorities. However, the results of these studies failed to be comparable directly with each other due to imprecise data sets, unmodified accounting methods of pasture and fossil energy, ignored secondary products, undefined process of calculating yield factors and improper biocapacity for biodiversity. In this paper, we elaborated on EF estimating methods from six categories of consumption in order to overcome the limitations above. We adopted precise data and revised methods, calculated EF of some secondary products, introduced weighted factor to calculate yield factors and adjusted biocapacity by an appropriate amount. Meanwhile, we investigated the resource consumption of Liaoning Province in 2006 to assess EF. Its results showed that Liaoning Province overused its natural capital and was in an unsustainable state. We concluded that two specific problems that had arisen in EF assessment and gave some suggestions for Liaoning Province to improve its unsustainable state.展开更多
Environmental investment must change its direction from end-investment to multi-investment, such as ecological construction, recycling economy and environmental protection. Only it can meet the needs of breaking the b...Environmental investment must change its direction from end-investment to multi-investment, such as ecological construction, recycling economy and environmental protection. Only it can meet the needs of breaking the bottleneck of resources and environment for Chinese sustainable development. And the transition can hero us realize low-ost and highspeedy increasing of economy, as well as the construction of ecological health, beautiful environment economic development and harmonious new society. Material recycling in ecosystem can run well by self-organization and self-regulation by nature with low-cost and even non-cost. So, the environmental investment in ecological construction should be the profits maximum investment. But it needs country's support in financial policy on ecological or environmental compensation. Recycling economy is a brand-new pattern of economic growth, which formed gradually in the course of mankind exploring and practicing sustainable development. Fountainhead prevention, reducing and whole processing control are its significant characteristics, which are digerent from any former economic and environmental protection system. Investing in technology development and relevant industry of recycling economy should be the other major field of environment investment in China in the future.展开更多
Physical methods show great potential and advantages on comprehensive reutilization of waste printed circuit boards (PCBs) because of lower investment and operation cost, higher efficiency and environment friendliness...Physical methods show great potential and advantages on comprehensive reutilization of waste printed circuit boards (PCBs) because of lower investment and operation cost, higher efficiency and environment friendliness. However, metals contained in fine fraction of PCBs cannot be recovered effectively by conventional equipments such as high tension electrostatic separator or shaking table. In the paper, this conundrum was resolved successfully with the enhanced Falcon SB concentrator. The separation mechanism of Falcon SB concentrator was analyzed and main factors affecting separation efficiency such as magnitude of rotation frequency of bowl, water counter pressure and slurry concentration of feed were studied and interaction of factors above also were investigated using Design-Expert software. Experiment results show that complete liberation degree and great difference of density between metals and nonmetals are suitable to recover metals from -74 μm PCBs using enhanced Falcon SB concentrator and 80.77 % integration efficiency can be achieved when slurry concentration of feed is 40 g/L with the water counter pressure of 0.01 MPa and rotation frequency of 50 Hz.展开更多
Analytic Network Process(ANP) was used in comprehensive evaluation of large infrastructure project plan. An model including social economy, ecological environment and resources was established with ANP method. The eva...Analytic Network Process(ANP) was used in comprehensive evaluation of large infrastructure project plan. An model including social economy, ecological environment and resources was established with ANP method. The evaluation pattern of hierarchy structure and comprehensive evaluation method for quantity and quality of large infrastructure project were put forward, which provides an effective way to evaluate the large infrastructure project plan. Quantitative analysis indicated that the internal dependence relation of hierarchy structure has influence on ranking results of plan. It is suggested that considering the internal relation can helps managers make effective decisions.展开更多
On the foundation of analyzing the closed loop logistics chain of product with multi-lifecycle, the connotation of environmental value is set forth, recurring to such conceptions as supply chain and value chain. The p...On the foundation of analyzing the closed loop logistics chain of product with multi-lifecycle, the connotation of environmental value is set forth, recurring to such conceptions as supply chain and value chain. The plotting rules about disassembly tree are discussed in detail. The reachable matrix R of components’ disas- sembly is introduced into distinguishing if disassembly is needed, in combination with disassembly-deciding vector X. Furthermore, the arithmetic of disassembly cost is put forward. And the cost-benefits of components’ reusing, materials’ recycling, safety disposing are dissertated based on the activity-based costing. Then the 0-1 goal-programming model on product recovery processing is established, with components’ demotion calculated. In addition, taking the PC’s recovery processing for example, we put it into application.展开更多
The philosophical root of all human beings’ existence crisis in the contemporary times is the philosophy of the unlimited theory. The inner spiritual supporting force is the construction from its theoretical reason t...The philosophical root of all human beings’ existence crisis in the contemporary times is the philosophy of the unlimited theory. The inner spiritual supporting force is the construction from its theoretical reason to its scientific reason. Its essential ideas stem from the people-centered theory, the view of happiness in the material- purposed theory, the communist life style, the material hegemonist principle, and the rational action principles of economic technology. In the 21st century, in order to deal with the dangerous situation of human beings’ exist- ence from the root, the philosophy of the limitation theory must be established, which has the eco-reason as the value support, integrates all the original wisdom of human beings and reflects human’s spiritual needs of the age as well as the direction of human future development. The whole percept of this new philosophy is that “all things have souls”; its basic law of existence is “the ceaseless life circle”; its survival goal is the view of happiness in the harmony of material and spirit; its social action guidance and principle are (environment, society, humanity) the environment ecologism and the integral-and-mutual action principle (of human beings &society, individual &society, and present age & posterity).展开更多
The inexplicit efficiency of environmental property rights lies in its fuzziness. Based on the character of environmental property rights discussed, unit environment shows intra relationship between efficiency and dut...The inexplicit efficiency of environmental property rights lies in its fuzziness. Based on the character of environmental property rights discussed, unit environment shows intra relationship between efficiency and duty of environmental property rights, and constructs a symmetrical system arrangement. Through analyzing the possibility and feasibility of unit environmental property rights, the significance of symmetrical system arrangement to avoid the inexplicit efficiency of environmental property rights is discussed in this dissertation from the aspect of the validity of offering and implementing system.展开更多
Co-integration theory has been employed in this paper and Granger causes are found between urbanization rate and GDP, between capital stock and GDP. Scenario analysis of GDP is performed using the GDP model establishe...Co-integration theory has been employed in this paper and Granger causes are found between urbanization rate and GDP, between capital stock and GDP. Scenario analysis of GDP is performed using the GDP model established in the paper. The energy consumptions in Germany, Japan and other developed countries are analyzed and compared with the energy consumption in China. Environmental friendly scenario of energy demand and CO2 emissions for sustainable China has been formed based on the results of comparison. Under environmental friendly scenario, the primary energy consumption will be 4.31 billion ton coal equivalence (tee) and CO2 emissions will be 1.854 billion t-c in 2050; energy per capital will be 3.06 tee that is 1.8 times of energy consumed in 2005 in China and 51% of consumed energy per capital in Japan in 2003. In 2050, the energy requirement of unit GDP will be 20% lower than that of Germany in 2003, but will be still 37% higher than that in Japan in 2003. It is certain that to fulfill the environmental friendly Scenario of energy demand and CO2 emissions is a difficult task and it needs long term efforts of the whole society, not only in production sectors but also in service and household sectors,展开更多
To making the decision of the developing blue prints,ideal point method was selected to estimate the life cycle cost with effectiveness of torpedo.At the same time,the concept of grey relational entropy of the grey sy...To making the decision of the developing blue prints,ideal point method was selected to estimate the life cycle cost with effectiveness of torpedo.At the same time,the concept of grey relational entropy of the grey system theory was adopted to compute the distance between each blue print and the ideal point(or negative ideal point).The blue print,nearest to the ideal point and farthest to the negative ideal point,is the best one.As an example,four blue prints of torpedo were estimated.The result indicates the practical value of this method.展开更多
This paper presents and analyses the differences in the eco-models implemented worldwide (such as whether and how carbon taxes being "recycled"), or in their efficiency parameters (inconsistent parameter values t...This paper presents and analyses the differences in the eco-models implemented worldwide (such as whether and how carbon taxes being "recycled"), or in their efficiency parameters (inconsistent parameter values that account for different results). This is the assumption that a real tradeoff exists between the production of environmental goods. The present article empirically proves that something must be given up in order to gain something else, and once equations are specified to trace out the path of the economy over time, the natural economic formulation of such equations will embody the notion of economic and bio-tradeoffs.展开更多
To protect environment, and to comply with the IMO's (International Maritime Organization) newest regulations about ship's SOx emission. This thesis illustrates a closed recycling absorb system based on NaOH solut...To protect environment, and to comply with the IMO's (International Maritime Organization) newest regulations about ship's SOx emission. This thesis illustrates a closed recycling absorb system based on NaOH solution recycling particularly for SOx onboard. The goal is to use NaOH solution to absorb SOx, and reduce the damage the ships made towards environment. The thesis analyzes the main features that could influence the absorption of SOx on board, and the precipitations during the experiment. To reveal that NaOH solution is very highly effective and economic in absorption of SOx on ships by this experiment, and to set a theoretical basic fundamental for future application of alkali solution recycling absorption system for SOx.展开更多
基金Supported by the Key Research Program of Frontier Sciences of CAS(QYZDJ-SSWJSC021)the Science and Technology Cooperation for Yunnan Provinces and CAS(2016IB002)+1 种基金Science and Technology Service Network Initiative of CAS(KFJ-SW-STS-148)National Natural Science Foundation of China(21506233,51402303,21606241,51374191)
文摘Traditionally,Ag-containing solid wastes are leached by nitric acid in order to recycle the noble metal.However,the huge amounts of emission of toxic nitrogen oxides demand the development of a new method for silver recycling.Recently,considering the Ce(Ⅳ)solution could be regenerated with electrolyzation method,our group invented a novel environmentally friendly process by using Ce(Ⅳ)as the oxidant to dissolve silver from the spent Ag/ɑ-Al_2O_3 catalysts without NO_x emission.To find out the optimal parameters,in this work,the leaching reaction was thoroughly investigated with respect to the temperature,oxidant and HNO_3 concentrations,stirring speed,and time.The optimized leaching reaction gave the leaching silver rate 99.8% in 1 h.The kinetic plots suggested a shrinking core model with the internal diffusion-controlled process and the activation energy of 38.83 k J·mol^(-1).The order in which the experimental conditions influence the reaction was determined through orthogonal analysis:temperature N oxidant concentration N HNO_3 concentration N stirring speed.
基金Project (No. 30370275) supported by the National Natural Science Foundation of China
文摘Biomineralization of Si by plants into phytolith formation and precipitation of Si into clays during weathering are two important processes of silicon’s biogeochemical cycle. As a silicon-accumulating plant, the widely distributed and woody Phyl-lostachys heterocycla var. pubescens (moso bamboo) contributes to storing silicon by biomineralization and, thus, prevents eu-trophication of nearby waterbodies through silicon’s erosion of soil particles. A study on the organic pool and biological cycle of silicon (Si) of the moso bamboo community was conducted in Wuyishan Biosphere Reserve, China. The results showed that: (1) the standing crop of the moso bamboo community was 13355.4 g/m2, of which 53.61%, 45.82% and 0.56% are represented by the aboveground and belowground parts of moso bamboos, and the under-story plants, respectively; (2) the annual net primary production of the community was 2887.1 g/(m2·a), among which the aboveground part, belowground part, litterfalls, and other fractions, accounted for 55.86%, 35.30%, 4.50% and 4.34%, respec-tively; (3) silicon concentration in stem, branch, leaf, base of stem, root, whip of bamboos, and other plants was 0.15%, 0.79%, 3.10%, 4.40%, 7.32%, 1.52% and 1.01%, respectively; (4) the total Si accumulated in the standing crop of moso bamboo com-munity was 448.91 g/m2, with 99.83% of Si of the total community stored in moso bamboo populations; (5) within moso bamboo community, the annual uptake, retention, and return of Si were 95.75, 68.43, 27.32 g/(m2·a), respectively; (6) the turnover time of Si, which is the time an average atom of Si remains in the soil before it is recycled into the trees or shrubs, was 16.4 years; (7) the enrichment ratio of Si in the moso bamboo community, which is the ratio of the mean concentration of nutrients in the net primary production to the mean concentration of nutrients in the biomass of a community, was 0.64; and lastly, (8) moso bamboo plants stored about 1.26×1010 kg of silicon in the organic pool made up by the moso bamboo forests in the subtropical area of China.
文摘Fire is quite a common natural phenomenon closely related to forest hydrology in forest ecosystem. The influence of fire on water is indirectly manifested in that the post fire changes of vegetation, ground cover, soil and environment affect water cycle, water quality and aquatic lives. The effect varies depending upon fire severity and frequency. Light wildland fires or prescribed burnings do not affect hydrology regime significantly but frequent burnings or intense fires can cause changes in hydrology regime similar to that caused clear cutting.
文摘Global water security is a severe issue that threatens human health and well-being. Finding sustainable alternative water resources has become a matter of great urgency. For coastal urban areas, desalinated seawater could serve as a freshwater supply. However, since 20%-30% of the water supply is used for flushing waste from the city, seawater with simple treatment could also partly replace the use of freshwater. In this work, the freshwater saving potential and environmental impacts of the urban water system (water-wastewater closed loop) adopting seawater desalination, seawater for toilet flushing (SWTF), or reclaimed water for toilet flushing (RWTF) are compared with those of a conventional freshwater system, through a life-cycle assessment and sensitivity analysis. The potential applications of these processes are also assessed. The results support the environmental sustainability of the SWTF approach, but its potential application depends on the coastal distance and effective population density of a city. Developed coastal cities with an effective population density exceeding 3000 persons.km-2 and located less than 30 km from the seashore (for the main pipe supplying seawater to the city) would benefit from applying SWTF, regardless of other impact parameters. By further applying the sulfate reduction, autotrophic denitrification, and nitrification integrated (SANI) process for wastewater treatment, the maximum distance from the seashore can be extended to 60 km. Considering that most modern urbanized cities fulfill these criteria, the next generation of water supply systems could consist of a freshwater supply coupled with a seawater supply for sustainable urban development.
文摘The crushing performance of printed circuit board (PCB) was studied on several crushers. The results show that PCB is a material which is difficult to crush. The crushing performance of PCB with disk crusher, especially vibration grinding, which has cut or impact action, excels that of jaw crusher or roller crusher. The PCB scrap is worthwhile to recycle using variety of modern characterization methods. When compared with natural resources, this material stream remains a rich precious metal and nonferrous metals. In PCB scrap, metals account for 47% of the total material composition, in which there exists 19.66% copper, 11.47% iron, 3.93% lead, 300 g/t gold and 510 kg/t silver, etc. In addition, the PCB scrap contains 27% of plastics and 26% of refractory oxides.
基金Projects 40371113 supported by the National Natural Science Foundation of China and OF060096Young Foundation of China University of Mining &Technology
文摘Based on an analysis of our research results and the main problems relating to urban rainwater treatment, we propose a new approach to urban rainwater management in China. The necessity and feasibility of such a new approach are discussed. From an ecological point of view all components of the global system, including residents living in cities, have the same right to enjoy rainwater. Therefore, urban rainwater should neither be simply drained as waste water, nor be completely harvested as a kind of resource. The objective of this new approach is to maintain the natural hydrological cycle in urban areas during urbanization. When necessary, it could also be used to regulate the amount of runoff, evaporation and infiltration in a city in order to rehabilitate the hydrological cycle given the local conditions. Three basic principles should be adopted in rainwater management, i.e., separation of rainfall from sewage, limited utilization and small and decentralized facilities. Four methods can be used for urban rainwater management: rainwater harvest, rainwater infiltration, rainwater storage and rainwater pipes. The natural hydrological cycle in urban areas could be rehabilitated through rainwater management, which is of great importance for sustainable development of our cities.
文摘Ecological footprint (EF) has received considerable attention as a useful indicator in the context of sustainable development. So far, EF has been used in numerous studies by academies, organizations and government authorities. However, the results of these studies failed to be comparable directly with each other due to imprecise data sets, unmodified accounting methods of pasture and fossil energy, ignored secondary products, undefined process of calculating yield factors and improper biocapacity for biodiversity. In this paper, we elaborated on EF estimating methods from six categories of consumption in order to overcome the limitations above. We adopted precise data and revised methods, calculated EF of some secondary products, introduced weighted factor to calculate yield factors and adjusted biocapacity by an appropriate amount. Meanwhile, we investigated the resource consumption of Liaoning Province in 2006 to assess EF. Its results showed that Liaoning Province overused its natural capital and was in an unsustainable state. We concluded that two specific problems that had arisen in EF assessment and gave some suggestions for Liaoning Province to improve its unsustainable state.
文摘Environmental investment must change its direction from end-investment to multi-investment, such as ecological construction, recycling economy and environmental protection. Only it can meet the needs of breaking the bottleneck of resources and environment for Chinese sustainable development. And the transition can hero us realize low-ost and highspeedy increasing of economy, as well as the construction of ecological health, beautiful environment economic development and harmonious new society. Material recycling in ecosystem can run well by self-organization and self-regulation by nature with low-cost and even non-cost. So, the environmental investment in ecological construction should be the profits maximum investment. But it needs country's support in financial policy on ecological or environmental compensation. Recycling economy is a brand-new pattern of economic growth, which formed gradually in the course of mankind exploring and practicing sustainable development. Fountainhead prevention, reducing and whole processing control are its significant characteristics, which are digerent from any former economic and environmental protection system. Investing in technology development and relevant industry of recycling economy should be the other major field of environment investment in China in the future.
基金Project 200360290015 supported by the Doctoral Program of Higher Education, China Ministry of Education
文摘Physical methods show great potential and advantages on comprehensive reutilization of waste printed circuit boards (PCBs) because of lower investment and operation cost, higher efficiency and environment friendliness. However, metals contained in fine fraction of PCBs cannot be recovered effectively by conventional equipments such as high tension electrostatic separator or shaking table. In the paper, this conundrum was resolved successfully with the enhanced Falcon SB concentrator. The separation mechanism of Falcon SB concentrator was analyzed and main factors affecting separation efficiency such as magnitude of rotation frequency of bowl, water counter pressure and slurry concentration of feed were studied and interaction of factors above also were investigated using Design-Expert software. Experiment results show that complete liberation degree and great difference of density between metals and nonmetals are suitable to recover metals from -74 μm PCBs using enhanced Falcon SB concentrator and 80.77 % integration efficiency can be achieved when slurry concentration of feed is 40 g/L with the water counter pressure of 0.01 MPa and rotation frequency of 50 Hz.
文摘Analytic Network Process(ANP) was used in comprehensive evaluation of large infrastructure project plan. An model including social economy, ecological environment and resources was established with ANP method. The evaluation pattern of hierarchy structure and comprehensive evaluation method for quantity and quality of large infrastructure project were put forward, which provides an effective way to evaluate the large infrastructure project plan. Quantitative analysis indicated that the internal dependence relation of hierarchy structure has influence on ranking results of plan. It is suggested that considering the internal relation can helps managers make effective decisions.
基金Supported by the National Natural Science Foundation of China(No.70472080)and Shanghai Shuguang Planning Program(No.70472080).
文摘On the foundation of analyzing the closed loop logistics chain of product with multi-lifecycle, the connotation of environmental value is set forth, recurring to such conceptions as supply chain and value chain. The plotting rules about disassembly tree are discussed in detail. The reachable matrix R of components’ disas- sembly is introduced into distinguishing if disassembly is needed, in combination with disassembly-deciding vector X. Furthermore, the arithmetic of disassembly cost is put forward. And the cost-benefits of components’ reusing, materials’ recycling, safety disposing are dissertated based on the activity-based costing. Then the 0-1 goal-programming model on product recovery processing is established, with components’ demotion calculated. In addition, taking the PC’s recovery processing for example, we put it into application.
文摘The philosophical root of all human beings’ existence crisis in the contemporary times is the philosophy of the unlimited theory. The inner spiritual supporting force is the construction from its theoretical reason to its scientific reason. Its essential ideas stem from the people-centered theory, the view of happiness in the material- purposed theory, the communist life style, the material hegemonist principle, and the rational action principles of economic technology. In the 21st century, in order to deal with the dangerous situation of human beings’ exist- ence from the root, the philosophy of the limitation theory must be established, which has the eco-reason as the value support, integrates all the original wisdom of human beings and reflects human’s spiritual needs of the age as well as the direction of human future development. The whole percept of this new philosophy is that “all things have souls”; its basic law of existence is “the ceaseless life circle”; its survival goal is the view of happiness in the harmony of material and spirit; its social action guidance and principle are (environment, society, humanity) the environment ecologism and the integral-and-mutual action principle (of human beings &society, individual &society, and present age & posterity).
文摘The inexplicit efficiency of environmental property rights lies in its fuzziness. Based on the character of environmental property rights discussed, unit environment shows intra relationship between efficiency and duty of environmental property rights, and constructs a symmetrical system arrangement. Through analyzing the possibility and feasibility of unit environmental property rights, the significance of symmetrical system arrangement to avoid the inexplicit efficiency of environmental property rights is discussed in this dissertation from the aspect of the validity of offering and implementing system.
文摘Co-integration theory has been employed in this paper and Granger causes are found between urbanization rate and GDP, between capital stock and GDP. Scenario analysis of GDP is performed using the GDP model established in the paper. The energy consumptions in Germany, Japan and other developed countries are analyzed and compared with the energy consumption in China. Environmental friendly scenario of energy demand and CO2 emissions for sustainable China has been formed based on the results of comparison. Under environmental friendly scenario, the primary energy consumption will be 4.31 billion ton coal equivalence (tee) and CO2 emissions will be 1.854 billion t-c in 2050; energy per capital will be 3.06 tee that is 1.8 times of energy consumed in 2005 in China and 51% of consumed energy per capital in Japan in 2003. In 2050, the energy requirement of unit GDP will be 20% lower than that of Germany in 2003, but will be still 37% higher than that in Japan in 2003. It is certain that to fulfill the environmental friendly Scenario of energy demand and CO2 emissions is a difficult task and it needs long term efforts of the whole society, not only in production sectors but also in service and household sectors,
基金the Doctorate Foundation of Northwestern Polytechnical University (Grant No.CX200304)
文摘To making the decision of the developing blue prints,ideal point method was selected to estimate the life cycle cost with effectiveness of torpedo.At the same time,the concept of grey relational entropy of the grey system theory was adopted to compute the distance between each blue print and the ideal point(or negative ideal point).The blue print,nearest to the ideal point and farthest to the negative ideal point,is the best one.As an example,four blue prints of torpedo were estimated.The result indicates the practical value of this method.
文摘This paper presents and analyses the differences in the eco-models implemented worldwide (such as whether and how carbon taxes being "recycled"), or in their efficiency parameters (inconsistent parameter values that account for different results). This is the assumption that a real tradeoff exists between the production of environmental goods. The present article empirically proves that something must be given up in order to gain something else, and once equations are specified to trace out the path of the economy over time, the natural economic formulation of such equations will embody the notion of economic and bio-tradeoffs.
文摘To protect environment, and to comply with the IMO's (International Maritime Organization) newest regulations about ship's SOx emission. This thesis illustrates a closed recycling absorb system based on NaOH solution recycling particularly for SOx onboard. The goal is to use NaOH solution to absorb SOx, and reduce the damage the ships made towards environment. The thesis analyzes the main features that could influence the absorption of SOx on board, and the precipitations during the experiment. To reveal that NaOH solution is very highly effective and economic in absorption of SOx on ships by this experiment, and to set a theoretical basic fundamental for future application of alkali solution recycling absorption system for SOx.