期刊文献+
共找到42篇文章
< 1 2 3 >
每页显示 20 50 100
工艺装备柔性化技术在轨道客车系列化生产中的应用
1
作者 夏丽芳 《黑龙江科技信息》 2016年第4期89-89,共1页
工艺装备柔性化技术在轨道客车系列化生产中的应用,对我国轨道客车系列化生产有着积极的作用。再加之,我国轨道客车正处于发展阶段,正需要先进的技术加以支持,而工艺装备柔性化技术,无疑是做好的选择。本文主要通过对铝合金车体柔性工... 工艺装备柔性化技术在轨道客车系列化生产中的应用,对我国轨道客车系列化生产有着积极的作用。再加之,我国轨道客车正处于发展阶段,正需要先进的技术加以支持,而工艺装备柔性化技术,无疑是做好的选择。本文主要通过对铝合金车体柔性工艺装备的详细介绍,分析了组装柔性化工艺装置,希望能够为我国轨道客车未来的发展提供借鉴。 展开更多
关键词 工艺装备 柔性化技术 轨道客车 系统化生产 应用
下载PDF
Interannual Variation in Terrestrial Ecosystem Carbon Fluxes in China from 1981 to 1998 被引量:35
2
作者 曹明奎 陶波 +2 位作者 李克让 邵雪梅 Stephen D PRIENCE 《Acta Botanica Sinica》 CSCD 2003年第5期552-560,共9页
A dynamic biogeochemical model was used to estimate the responses of China's terrestrial net primary productivity (NPP), soil heterotrophic respiration (HR) and net ecosystem productivity (NEP) to changes in clima... A dynamic biogeochemical model was used to estimate the responses of China's terrestrial net primary productivity (NPP), soil heterotrophic respiration (HR) and net ecosystem productivity (NEP) to changes in climate and atmospheric CO2 from 1981 to 1998. Results show that China's total NPP varied between 2.89 and 3.37 Gt C/a and had an increasing trend by 0.32% per year, HR varied between 2.89 and 3.21 Gt C/a and grew by 0.40% per year, Annual NEP varied between -0.32 and 0.25 Gt C but had no statistically significant interannual trend. The positive mean NEP indicates that China's terrestrial ecosystems were taking up carbon with a total carbon sequestration of 1.22 Gt C during the analysis period. The terrestrial NEP in China related to climate and atmospheric CO2 increases accounted for about 10% of the world's total and was similar to the level of the United States in the same period. The mean annual NEP for the analysis period was near to zero for most of the regions in China, but significantly positive NEP occurred in Northeast China Plain, the southeastern Xizang (Tibet) and Huang-Huai-Hai Plain, and negative NEP occurred in the Da Hinggan Mountains, Xiao Hinggan Mountains, Loess Plateau and Yunnan-Guizhou Plateau. China's climate at the time was warm and dry relative to other periods, so the estimated NEP is probably lower than the average level. China's terrestrial NEP may increase if climate becomes wetter but is likely to continue to decrease if the present warming and drying trend sustains. 展开更多
关键词 China net primary productivity (NPP) soil heterotrophic respiration (HR) net ecosystem productivity (NEP) climate change
下载PDF
Review of study on mineralization, saturation and cycle of Nitrogen in forest ecosystems 被引量:4
3
作者 杨金艳 范晶 《Journal of Forestry Research》 SCIE CAS CSCD 2003年第3期239-243,共5页
Nitrogen is one of the most important elements that can limit plant growth in forest ecosystems. Studies of nitrogen mineralization, nitrogen saturation and nitrogen cycle in forest ecosystems is very necessary for un... Nitrogen is one of the most important elements that can limit plant growth in forest ecosystems. Studies of nitrogen mineralization, nitrogen saturation and nitrogen cycle in forest ecosystems is very necessary for understanding the productivity of stand, nutrient cycle and turnover of nitrogen of forest ecosystems. Based on comparison and analysis of domestic and in-ternational academic references related to studies on nitrogen mineralization, nitrogen saturation and nitrogen cycle in recent 10 years, the current situation and development of the study on these aspects, and the problems existed in current researches were reviewed. At last, some advices were given for future researches. 展开更多
关键词 NITROGEN Nitrogen mineralization Nitrogen saturation Climate change Nitrogen cycling
下载PDF
Conservation priority for endemic birds of China's Mainland based on a phylogenetic framework 被引量:5
4
作者 陈有华 《Chinese Birds》 CSCD 2013年第3期248-253,共6页
In this report, a conservation priority scenario for endemic birds of China's Mainland is proposed from a phylogenetic perspective. By utilizing and comparing seven phylogenetic diversity (PD) indices, the study s... In this report, a conservation priority scenario for endemic birds of China's Mainland is proposed from a phylogenetic perspective. By utilizing and comparing seven phylogenetic diversity (PD) indices, the study shows that the top ifve endemic birds with high conservation priority are Ar-borophila ardens, A. gingica, A. ruifpectus, Lophophorus lhuysii and Alectoris magna respectively. The ranking of species, based on the IUCN Red List and PD indices, were compared by means of a Wilcox signed rank test and Pearson’s correlation, drawing the inference that the PD ranking of endemic birds for China's Mainland shows a distinct and statistically signiifcant difference from the IUCN rank-ing. Therefore, the ranking of conservation priority for endemic birds of China using PD indices might offer new insights on species conservation from an evolutionary-heritage perspective, serving as a complement to the IUCN ranking. 展开更多
关键词 evolutionary heritage systematic conservation planning phylogenetic theory
下载PDF
Systematic Analysis of Carbon Dioxide Activation of Waste Tire by Factorial Design 被引量:1
5
作者 P.P.M.Fung W.H.Cheung G.McKay 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2012年第3期497-504,共8页
In this study, waste tire was used as raw material for the production of activated carbons through pyrolysis. 'Fire char was first produced by carbomzation at 550℃ under nitrogen. A two tactortal design was used to ... In this study, waste tire was used as raw material for the production of activated carbons through pyrolysis. 'Fire char was first produced by carbomzation at 550℃ under nitrogen. A two tactortal design was used to optimize the production of activated carbon from tire char. The effects of several factors controlling the activation process, such as temperature (.830-930℃), time (2-6h) and percentage ot carbon dioxide (70%-100%) were investigated. The production was described mathematically as a function of these three factors. First order modeling equations were developed for surface area, yield and mesopore volume. It was concluded that the yield, BET surface area and mesopore volume of activated carbon were most sensitive to activation temperature and time while percentage of carbon dioxide in the activation gas was a less significant factor. 展开更多
关键词 activated carbon waste tire factorial design carbon dioxide
下载PDF
Multi-objective optimization of methane production system from biomass through anaerobic digestion 被引量:1
6
作者 Weijun Li Jakob Kj?bsted Huusom +3 位作者 Zhimao Zhou Yi Nie Yajing Xu Xiangping Zhang 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2018年第10期2084-2092,共9页
This work addressed the multi-objective optimization of a biogas production system considering both environmental and economic criteria. A mixed integer non-linear programming(MINLP) model was established and solved w... This work addressed the multi-objective optimization of a biogas production system considering both environmental and economic criteria. A mixed integer non-linear programming(MINLP) model was established and solved with non-dominated sorting genetic algorithm Ⅱ, from which the Pareto fronts, the optimal technology combinations and operation conditions were obtained and analyzed. It's found that the system is feasible in both environmental and economic considerations after optimization. The most expensive processing section is decarbonization; the most expensive equipment is anaerobic digester; the most power-consuming processing section is digestion, followed by decarbonization and waste management. The positive green degree value on the process is attributed to processing section of digestion and waste management. 3:1 chicken feces and corn straw, solar energy, pressure swing adsorption and 3:1 chicken feces and rice straw, solar energy, pressure swing adsorption are turned out to be two robust technology combinations under different prices of methane and electricity by sensitivity analysis. The optimization results provide support for optimal design and operation of biogas production system considering environmental and economic objectives. 展开更多
关键词 Biogas production system MINLP Multi-objective optimization Non-dominated sorting genetic algorithm Green degree value
下载PDF
Options for Managing Livestock Production Systems to Adapt to Climate Change 被引量:1
7
作者 Evangelia N. Sossidou Eleni Tsiplakou George Zervas 《Journal of Earth Science and Engineering》 2014年第7期415-427,共13页
This paper discusses recent research findings together with management schemes in preventing and managing of thermal stress by handling external and internal factors in livestock production systems. Preventive measure... This paper discusses recent research findings together with management schemes in preventing and managing of thermal stress by handling external and internal factors in livestock production systems. Preventive measures against thermal stress are described as basic structural adjustments and the modifications that can be implemented readily, according to animal health and welfare requirements and refer to (1) environmental modification and thermal comfort in various housing systems; (2) action on animals, such as genetic selection for breeds resistant to infectious disease, parasites and climate extremes; (3) action on feed and (4) action on staff handling the animals. Moreover, measures to be taken both in situations of chronic thermal stress and heat or cold strokes are presented as they are applied to (1) limit stress, (2) monitor the temperature felt by animals, (3) adapt diet and drinking water supplies and (4) correct physiological imbalances. Examples are given for different farm species (cattle, sheep, goat, poultry and pigs) and different production systems (intensive, extensive and alternative). The paper concludes with a practical guide for the effective handling of thermal stress at farm level, summarizing the results from recent research studies on the specific topic. 展开更多
关键词 Livestock production MANAGEMENT thermal comfort.
下载PDF
Mathematical models and expert system for grate-kiln process of iron ore oxide pellet production.Part Ⅱ:Rotary kiln process control 被引量:7
8
作者 范晓慧 王祎 陈许玲 《Journal of Central South University》 SCIE EI CAS 2012年第6期1724-1727,共4页
Rotary kiln process for iron ore oxide pellet production is hard to detect and control.Construction of one-dimensional model of temperature field in rotary kiln was described.And the results lay a solid foundation for... Rotary kiln process for iron ore oxide pellet production is hard to detect and control.Construction of one-dimensional model of temperature field in rotary kiln was described.And the results lay a solid foundation for online control.Establishment of kiln process control expert system was presented,with maximum temperature of pellet and gas temperature at the feed end as control cores,and interval estimate as control strategy.Software was developed and put into application in a pellet plant.The results show that control guidance of this system is accurate and effective.After production application for nearly one year,the compressive strength and first grade rate of pellet are increased by 86 N and 2.54%,respectively,while FeO content is 0.05% lowered.This system can reveal detailed information of real time kiln process,and provide a powerful tool for online control of pellet production. 展开更多
关键词 mathematical model expert system one-dimensional temperature field rotary kiln iron ore oxide pellet
下载PDF
River Flow Control on the Phytoplankton Dynamics of Chesapeake Bay 被引量:1
9
作者 YU Qingyun WANG You +1 位作者 TANG Xuexi LI Ming 《Journal of Ocean University of China》 SCIE CAS 2013年第1期103-114,共12页
Recent observations support an emerging paradigm that climate variability dominates nutrient enrichment in costal eco-systems, which can explain seasonal and inter-annual variability of phytoplankton community composi... Recent observations support an emerging paradigm that climate variability dominates nutrient enrichment in costal eco-systems, which can explain seasonal and inter-annual variability of phytoplankton community composition, biomass (Chl-a), and primary production (PP). In this paper, we combined observation and modeling to investigate the regulation of phytoplankton dynamics in Chesapeake Bay. The year we chose is 1996 that has high river runoff and is usually called a 'wet year'. A 3-D physical-biogeochemical model based on ROMS was developed to simulate the seasonal cycle and the regional distributions of phytoplankton biomass and primary production in Chesapeake Bay. Based on the model results, NO3 presents a strong contrast to the river nitrate load during spring and the highest concentration in the bay reaches around 80 mmol Nm-3 . Compared with the normal year, phytoplankton bloom in spring of 1996 appears in lower latitudes with a higher concentration. Quantitative comparison between the modeled and observed seasonal averaged dissolved inorganic nitrogen concentrations shows that the model produces reliable results. The correlation coefficient r2 for all quantities exceeds 0.95, and the skill parameter for the four seasons is all above 0.95. 展开更多
关键词 river flow phytoplankton dynamics BLOOM light limitation Chesapeake Bay
下载PDF
Multidisciplinary design optimization for air-condition production system based on multi-agent technique 被引量:2
10
作者 杨海东 鄂加强 屈挺 《Journal of Central South University》 SCIE EI CAS 2012年第2期527-536,共10页
In order to guarantee the overall production performance of the multiple departments in an air-condition production industry, multidisciplinary design optimization model for production system is established based on t... In order to guarantee the overall production performance of the multiple departments in an air-condition production industry, multidisciplinary design optimization model for production system is established based on the multi-agent technology. Local operation models for departments of plan, marketing, sales, purchasing, as well as production and warehouse are formulated into individual agents, and their respective local objectives are collectively formulated into a multi-objective optimization problem. Considering the coupling effects among the correlated agents, the optimization process is carried out based on self-adaptive chaos immune optimization algorithm with mutative scale. The numerical results indicate that the proposed multi-agent optimization model truly reflects the actual situations of the air-condition production system. The proposed multi-agent based multidisciplinary design optimization method can help companies enhance their income ratio and profit by about 33% and 36%, respectively, and reduce the total cost by about 1.8%. 展开更多
关键词 multi-agent system production operation multidisciplinary optimization self-adaptive chaos optimization immune optimization algorithm
下载PDF
Study on Application of Mixed-Refrigerant Refrigeration in Ethylene Plant 被引量:1
11
作者 Zhang Wei Xu Xinru 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2009年第3期20-24,共5页
This paper focuses on the mixed-refrigerant refrigeration process flows which are applied in the cryogenic separation section of ethylene plant. Based on a 120 kt/a ethylene plant which employs a sequence separation p... This paper focuses on the mixed-refrigerant refrigeration process flows which are applied in the cryogenic separation section of ethylene plant. Based on a 120 kt/a ethylene plant which employs a sequence separation process flow and lowpressure demethanization system, the energy consumption of three refrigeration process flows(typical cascade refrigeration, binary refrigeration and tertiary refrigeration) was calculated by means of the ASPEN PLUS simulation software. An optimized mixed-refrigerant composition which achieved the minimum energy consumption of refrigeration systems was found out and the exergy loss was analyzed and compared. Results indicated that the energy consumption of typical cascade refrigeration and binary refrigeration systems was almost equal and that of tertiary refrigeration system was higher than the other two systems. Based on the current situation of production, the suggestions on production optimization and refrigeration process flow selection were put forward. 展开更多
关键词 ethylene plant mixed refrigerant REFRIGERATION EXERGY
下载PDF
Noise degradation system using Wiener filter and CORDIC based FFT/IFFT processor 被引量:2
12
作者 Yasodai A Ramprasad A V 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第10期3849-3859,共11页
On augmentation of past work, an effective Wiener filter and its application for noise suppression combined with a formed CORDIC based FFT/IFFT processor with improved speed were executed. The pipelined methodology wa... On augmentation of past work, an effective Wiener filter and its application for noise suppression combined with a formed CORDIC based FFT/IFFT processor with improved speed were executed. The pipelined methodology was embraced for expanding the execution of the system. The proposed Wiener filter was planned in such an approach to evacuate the iteration issues in ordinary Wiener filter. The division process was supplanted by a productive inverse and multiplication process in the proposed design. An enhanced design for matrix inverse with reduced computation complexity was executed. The wide-ranging framework processing was focused around IEEE-754 standard single precision floating point numbers. The Wiener filter and the entire system design was integrated and actualized on VIRTEX 5 FPGA stage and re-enacted to approve the results in Xilinx ISE 13.4. The results show that a productive decrease in power and area is developed by adjusting the proposed technique for speech signal noise degradation with latency of n/2 clock cycles and substantial throughput result per every 12 clock cycles for n-bit precision. The execution of proposed design is exposed to be 31.35% more effective than that of prevailing strategies. 展开更多
关键词 Wiener filter ITERATIONS power spectrum FFT/IFFT floating point noise suppression speech enhancement VLSI speed power area
下载PDF
The Production of Patents and Evolution of the Production of Knowledge around Snow Avalanches
13
作者 Luis G Lopez-Cobo 《Journal of Earth Science and Engineering》 2015年第1期76-85,共10页
Scientific research on snow avalanches is relatively modem, yet in constant and rapid evolution, as the multiple disciplines involved in its development will, in turn, become more specialized and more technical. Paten... Scientific research on snow avalanches is relatively modem, yet in constant and rapid evolution, as the multiple disciplines involved in its development will, in turn, become more specialized and more technical. Patents are part of research and knowledge production. The scientific community and policy makers are increasingly interested in production of knowledge collaboratively. Almost all of the research being conducted on snow avalanches uses technology, technique or instrumentation. One main objective of this study is to draw from the literature the many technologies, techniques and instrumentations that are being used in research related to avalanches. Thus, a textual analysis of the most significant literature in the field of snow avalanches was done. In this analysis, techniques, technologies and instrumentations have emerged. A patent search has been done in databases. Subsequently, patents were conceptualized. The proportion of applicants for patents is higher in industry than in universities. The measure of exploration of the ongoing sociocognitive transformations of science and technology systems presents a useful tool to conduct a study to explore these transformations. It would be interesting for the scientific community, but also for the industry, to elaborate concept mapping when applied to avalanche research, which would help in determining referents. 展开更多
关键词 AVALANCHES patents KNOWLEDGE conceptual map technology collaboration.
下载PDF
Futuristic Applications for Profitable Beef Production Systems
14
作者 SerapGOncü,Ozgül Anitas and Gokhan Gokce 《Journal of Environmental Science and Engineering(A)》 2017年第12期625-634,共10页
The growing demands for red meats of people also present opportunities for fattening as well as improved markets for the animals. Beef production is a highly profitable venture with return of premium to the farmer. Th... The growing demands for red meats of people also present opportunities for fattening as well as improved markets for the animals. Beef production is a highly profitable venture with return of premium to the farmer. The large scale beef farming must be meet economic criteria for sustainable production. It consists of buying healthy stock, feeding and fattening them to optimum carcass weight, and selling them at any time of the year. They are handled in such a way that maximum growth is achieved at the lowest possible cost. The lifespan of operation is shorter and the return of investment is relatively higher. In beef farms which has very high genetic value of breeding animals cannot be get the expected performance without the use of technology and automation systems. Beef herd management programs if can be used as effectively, farming will have many advantages for consumer, farmer and also animals. However, to obtain these advantages from this system, required to have knowledge of the functions and effective use of the functions. The large amount of data in the obtained on many issues related to animals, herd management and an individual unless used in decisions about animals, ensuring the heavy data flow, record keeping or assessment will not give the expected results. In this study, it has been aiming that the examined the technologic applications at beef farms for sustainable and profitable meat production. 展开更多
关键词 AUTOMATION INTENSIVE beef farms herd management PROFITABILITY
下载PDF
Nitrogen and phosphorus budgets of the Changjiang River estuary 被引量:2
15
作者 李祥安 俞志明 +2 位作者 宋秀贤 曹西华 袁涌铨 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2011年第4期762-774,共13页
Eutrophication has emerged as a key environmental problem in Chinese coastal waters, especially in the Changjiang (Yangtze) River estuary. In this area, large nutrient inputs result in frequent harmful algal blooms an... Eutrophication has emerged as a key environmental problem in Chinese coastal waters, especially in the Changjiang (Yangtze) River estuary. In this area, large nutrient inputs result in frequent harmful algal blooms and serious hypoxia in bottom waters. Four cruises were made in the estuary in 2006 to assess the concentration and distribution of dissolved inorganic nitrogen (DIN) and phosphorus (DIP). The concentration of DIN decreased gradually in a linear relationship with salinity from the river mouth to outer waters, while DIP was relatively more dispersed. A modified box budget method was used to estimate nutrient fluxes in the estuary and its adjacent waters. Water and nutrient budgets as well as primary production and denitrification rates were estimated from the box budget model. Estimated water residence time in the estuary was about 11 d. The turbid mixing zone released 33% of DIN and 49% of DIP, while in the adjacent outer sea 17.9 mmol DIN/m2·d and 0.36 mmol DIP/m2·d were fixed. Dissolved inorganic phosphorus was imported from the deep open sea waters, supporting primary production and population growth in this zone. Net ecosystem production (NEP) was calculated at 38.2 mmol/m2·d in the outer estuary and the estimated rate (N-fixation minus denitrification) was negative (1.92 mmol/m2·d), implying that a large amount of input nitrogen was taken up by algae and recycled through denitrification in bottom water and sediment. 展开更多
关键词 NITROGEN PHOSPHORUS NUTRIENTS TRANSPORT budget model Changjiang (Yangtze) River estuary
下载PDF
Self-Optimizing Flexible Assembly Systems
16
作者 Robert Schmitt Peter Loosen +6 位作者 Christian Brecher Alberto Pavim Max Funck Valentin Morasch Alexander Gatej Nicolas Pyschny Sebastian Haag 《Computer Technology and Application》 2011年第5期333-343,共11页
Today's production systems are demanded to exhibit an increased flexibility and mutability in order to deal with dynamically changing conditions, objectives and an increasing number of product variants within industr... Today's production systems are demanded to exhibit an increased flexibility and mutability in order to deal with dynamically changing conditions, objectives and an increasing number of product variants within industrial turbulent environments. Flexible automated systems are requested in order to improve dynamic production efficiency, e.g. robot-based hardware and PC-based controllers, but these usually induce a significantly higher production complexity, whereby the efforts for planning and programming, but also setups and reconfiguration, expand. In this paper a definition and some concepts of self-optimizing assembly systems are presented to describe possible ways to reduce the planning efforts in complex production systems. The concept of self-optimization in assembly systems will be derived from a theoretical approach and will be transferred to a specific application scenario---the automated assembly of a miniaturized solid state laser--where the challenges of unpredictable influences from e.g. component tolerances can be overcome by the help of self-optimization. 展开更多
关键词 Flexible assembly systems SELF-OPTIMIZATION multi agent systems COGNITION tolerance matching sensor data fusion.
下载PDF
A Framework for Implementation of Green Manufacturing in Customized Products Manufacturing Enterprises
17
作者 GU Zhenyu ZHU Yaoyao XIANG Jilei 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2020年第3期370-376,共7页
An increase in public environmental awareness and pressures from the government’s determination to deal with environmental problems force manufacturers to implement green manufacturing(GM).However,since managers and ... An increase in public environmental awareness and pressures from the government’s determination to deal with environmental problems force manufacturers to implement green manufacturing(GM).However,since managers and stakeholders lack understanding of GM and its complexity,the manufacturing enterprise,especially the small and medium ones,are constantly facing the problems of how to make a reasonable decision for an environmental problem,and the adopted approaches have no clear payoffs.The customized design,flexible production,and diversified services in customized production make the problems more challenging.In order to solve this problem,this paper proposes a framework for the implementation of GM in customized products manufacturing enterprises(CPME).A three-layer framework,i.e.,the goal layer,the product life-cycle layer and the supporting layer,is designed to provide a methodology to help implement GM.In this model,the GM practice processes are divided into four stages from the life-cycle perspective,i.e.design,production,use,and disposal.The preliminary practice of GM in an electrical product manufacturing company is carried out,and the implementation effect shows that the system framework is helpful to make a comprehensive understanding of GM and to improve the operability of GM practices.The integrated product model is an effective way to integrate the life cycle data. 展开更多
关键词 green manufacturing IMPLEMENTATION system framework customized production
下载PDF
Flora, life form characteristics, and plan for the promotion of biodiversity in South Korea's Globally Important Agricultural Heritage System, the traditional Gudeuljang irrigated rice terraces in Cheongsando 被引量:9
18
作者 Hong Chul PARK Chaang Hveon OH 《Journal of Mountain Science》 SCIE CSCD 2017年第6期1212-1228,共17页
The objectives of this study were to analyze the biodiversity of the Traditional Gudeuljang Irrigated Rice Terraces in Cheongsando, South Korea's representative GIAHS(Globally Important Agricultural Heritage Syste... The objectives of this study were to analyze the biodiversity of the Traditional Gudeuljang Irrigated Rice Terraces in Cheongsando, South Korea's representative GIAHS(Globally Important Agricultural Heritage System) site, with reference to position and land-use features, and to develop a plan to promote agricultural biodiversity in the region. We confirmed approximately 54,000 m2 of Gudeuljang paddy fields by an on-site survey. Of the Traditional Gudeuljang Irrigated Rice Terraces confirmed by onsite inspection, our survey showed that approximately 24,000 m2 are currently being used as paddy fields, approximately 15,000 m2 are being used as dry fields, and approximately 14,000 m2 are fallow. In terms of other non-agricultural land use, there was grassland, including graveyards; artificial arboreal land, such as orchards, rivers and wetlands, and man-made facilities, such as roads and residences. We also confirmed that the Traditional Gudeuljang Irrigated Rice Terraces had higher plant species diversity than conventional terraced rice paddies, and there was a difference in life form characteristics between the two types. Although the superficial topsoil structure is thesame for the Traditional Gudeuljang Irrigated Rice Terraces(TGIRTs) and conventional terraced rice paddies, it is thought that the differences in the subsurface structure of the TGIRTs contribute greatly to species and habitat diversity. However, the TGIRTs in Cheongsando are facing degeneration, due to damage and reduction in agricultural activity. The main cause is the reduction in the number of farming households due to an aging population in Cheongsando. In order to address this problem, we proposed a management plan, related to fallow paddy fields in South Korea, to initiate voluntary activities in the TGIRTs. 展开更多
关键词 Globally Important Agricultural Heritage System Rice terrace Agricultural biodiversity Topsoil structure Gudeuljang
下载PDF
Cultivation of microalgae for biodiesel production:A review on upstream and downstream processing 被引量:7
19
作者 Xin Bei Tan Man Kee Lam +3 位作者 Yoshimitsu Uemura Jun Wei Lim Chung Yiin Wong Keat Teong Lee 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2018年第1期17-30,共14页
Fluctuating market price of fossil fuel and overwhelming emission of greenhouse gases to the atmosphere have resulted in climate change and have been a global concern in this decade. Hence, biodiesel has become an alt... Fluctuating market price of fossil fuel and overwhelming emission of greenhouse gases to the atmosphere have resulted in climate change and have been a global concern in this decade. Hence, biodiesel has become an alternative option to fossil diesel as it is renewable and environmentally friendly. Nevertheless, this alternative fuel that is usually derived from terrestrial oil crops will cause shortage in food supply and deforestation if mass production is realized. In recent years, cultivation of aquatic microorganism(particularly microalgae) to produce biodiesel is considered as a practical solution due to their high growth rate and ability to synthesize large quantity of lipid within their cell. However, the development of energy and cost-efficiency of microalgae cultivation system are the main issues in producing renewable microalgae biodiesel. Of late, wastewater or organic compost has been used as the cultivation medium as it can provide sufficient nutrients to sustain microalgae growth.Microalgae cultivation method and system are vitally important as these factors undoubtedly affect the final microalgae biomass and lipid yield. In this review, the cultivation system of microalgae, nutrients demanded for microalgae production, cell harvesting and drying, microalgae oil extraction, and utilization of microalgae biomass for biodiesel production are introduced and discussed. It is anticipated to convey clearer perspectives in upstream and downstream processes in microalgae-derived biodiesel production. 展开更多
关键词 Microalgae Cultivation Lipid Biodiesel Harvesting
下载PDF
A dynamic optimization model of an integrated coal supply chain system and its application 被引量:8
20
作者 PENG Hong-jun ZHOU Mei-hua +2 位作者 LIU Man-zhi ZHANG Yu HUANG Yan-bo 《Mining Science and Technology》 EI CAS 2009年第6期842-846,共5页
Various nodes,logistics,capital flows,and information flows are required to make systematic decisions concerning the operation of an integrated coal supply system. We describe a quantitative analysis of such a system.... Various nodes,logistics,capital flows,and information flows are required to make systematic decisions concerning the operation of an integrated coal supply system. We describe a quantitative analysis of such a system. A dynamic optimization model of the supply chain is developed. It has achieved optimal system profit under conditions guaranteeing a certain level of customer satisfaction. Applying this model to coal production of the Xuzhou coal mines allows recommendations for a more systematic use of washing and processing,transportation and sale resources for commercial coal production to be made. The results show that this model,which is scientific and effective,has an important value for making reasonable decisions related to complex coal enterprises. 展开更多
关键词 coal supply chain multiple linear regression customer satisfaction dynamic optimization model
下载PDF
上一页 1 2 3 下一页 到第
使用帮助 返回顶部