期刊文献+
共找到30篇文章
< 1 2 >
每页显示 20 50 100
Assessment on Energy Self-Sufficiency Rate for Building Integrated Photovoltaics and Fuel Cell System in Japan 被引量:3
1
作者 Akira Nishimura Satoshi Kitagawa +1 位作者 Masafumi Hirota Eric Hu 《Smart Grid and Renewable Energy》 2017年第6期195-211,共17页
A building integrated photovoltaic (PV) and fuel cell (FC) system is proposed for assessment of the energy self-sufficiency rate in a city in Japan. The electricity consumed in the building is mainly supplied by solar... A building integrated photovoltaic (PV) and fuel cell (FC) system is proposed for assessment of the energy self-sufficiency rate in a city in Japan. The electricity consumed in the building is mainly supplied by solar panels, while the gap between the energy demand and supply is solved by the FC that is powered by the H2 produced by water electrolysis with surplus power of PV. A desktop case study of using the proposed system in Tsu city which is located in central part of Japan, has been conducted. The results found that the self-sufficiency rates of PV system to electricity demand of households (RPV) during the daytime in April and July are higher than those in January and October. The results also reveal that the self-sufficiency rate of FC system to the electricity demand (RFC) is 15% - 38% for the day when the mean amount of horizontal solar radiation is obtained in January, April, July and October. In addition, it is found the optimum tilt angle of solar panel installed on the roof of the buildings should be 0 degree, i.e., placed horizontally. 展开更多
关键词 Smart Building Photovoltaics H2 PRODUCED by Water ELECTROLYSIS FUEL Cell self-sufficiency Rate
下载PDF
ROLE OF REMOTE SENSING IN ACHIEVING NATIONAL FOOD SELF-SUFFICIENCY AND FOOD SECURITY 被引量:1
2
作者 LI Deren 《Geo-Spatial Information Science》 2000年第2期1-5,共5页
This paper seeks to explore the role of Remote Sensing in solving the agriculture related problems, which are the basic issues of sustainable development.
关键词 remote sensing food self-sufficiency food security
下载PDF
Carbon Dioxide Emissions and Energy Self-Sufficiency of Woody Biomass Utilization for Residential Heating: A Case Study of Nishiwaga, Japan 被引量:1
3
作者 Daisuke Sawauchi Daisuke Kunii Yasutaka Yamamoto 《Journal of Environmental Protection》 2015年第4期321-327,共7页
Renewable energy sources, including bioenergy, are presently attracting considerable attention as possible substitutes for fossil fuels. Among the various sources of bioenergy, biomass can arguably play a significant ... Renewable energy sources, including bioenergy, are presently attracting considerable attention as possible substitutes for fossil fuels. Among the various sources of bioenergy, biomass can arguably play a significant role in the reduction of greenhouse gases and the provision of a stable energy supply. However, the use of fossil fuels continues in the production of bioenergy. Consequently, the overall extent to which biomass utilization for energy can reduce carbon dioxide emissions as a substitute for fossil fuels and whether this can improve the energy self-sufficiency rate remains largely unknown. This study responds to these questions using a case of a Japanese rural community using firewood for residential heating. The results showed that woody biomass utilization for energy is able to both reduce the dependence on fossil fuels and mitigate climate change. These findings offer new insights into the development of sustainability in rural communities. 展开更多
关键词 Carbon Dioxide Emissions ENERGY self-sufficiency WOODY Biomass BIOENERGY RESIDENTIAL Heating JAPAN
下载PDF
Sharp Decline in the Food Self-sufficiency Ratio in Japan and Its Future Prospects 被引量:2
4
作者 T. Kako 《Journal of Agricultural Science and Technology》 2010年第3期102-110,共9页
Most Japanese are enjoying rich and convenient dietary habits nowadays. However, majorities of Japanese are feeling anxiety about the future food supply because Japan's food self-sufficiency ratio has fallen most rap... Most Japanese are enjoying rich and convenient dietary habits nowadays. However, majorities of Japanese are feeling anxiety about the future food supply because Japan's food self-sufficiency ratio has fallen most rapidly in the last 45 years, and is lowest amongst countries with a population of more than 100 million. Major causes and mechanisms of the decline in the food self-sufficiency ratio over the last 45 years were analyzed. Drastic changes of dietary habits under rapid economic growth and sharp appreciation of the yen against the US dollar were found to be the major causes of the sharp decline of the food self-sufficiency ratio. Preliminary projections about the food self-sufficiency ratio in 2015 were carried out, and it was found that it will not be easy to achieve the policy goal of raising the food self-sufficiency ratio to 45% by 2015. 展开更多
关键词 Food self-sufficiency ratio dietary habit appreciation of the yen
下载PDF
A Quantitative Factorial Component Analysis to Investigate the Recent Changes of Japan’s Weight-Based Food Self-Sufficiency Ratio 被引量:1
5
作者 Kunihisa Yoshii Tatsuo Oyama 《American Journal of Operations Research》 2016年第1期44-60,共17页
We investigate the weight-based food self-sufficiency ratio (WSSR) for Japan over a 50-year period (1961-2011) by applying factorial component analysis technique in order to measure the changes of the WSSR quantitativ... We investigate the weight-based food self-sufficiency ratio (WSSR) for Japan over a 50-year period (1961-2011) by applying factorial component analysis technique in order to measure the changes of the WSSR quantitatively. Quantitative data analysis is employed to determine the drivers of those changes. Numerical results show that Japan experienced a drastic decline in its food self-sufficiency ratio (FSSR) during the above period. The factorial component analysis shows that such a decline was caused by the changes in the FSSR of the food groups/items, not in the quantity of the food supply. A number of characteristics of those changes are presented and a list of major food groups that have major impacts on the changes is constructed. The findings in this paper reiterate the alarming food security problem in Japan and provide clear insight into the causes of this problem. The findings in this study pick up where previous studies have left off, aid the food-related policy-making process and identify new ideas for future food research. 展开更多
关键词 Food self-sufficiency Ratio Food Security Factorial Component Analysis
下载PDF
Strategies for Promoting Rice Self-sufficiency in Sierra Leone
6
作者 Alphajoh Alhadi Bah 《Journal of Northeast Agricultural University(English Edition)》 CAS 2013年第4期78-86,共9页
Rice is the main food of Sierra Leoneans and an important source of employment and income for rural communities. According to the West African Rice Development Association report, annual consumption of rice is amongst... Rice is the main food of Sierra Leoneans and an important source of employment and income for rural communities. According to the West African Rice Development Association report, annual consumption of rice is amongst the highest in SubSaharan Africa(SSA), 104 kg. Mainly, small scale farmers who are resource poor on both the upland and various lowlands grow rice. Sierra Leone has not been able to produce enough rice to meet its local consumption demand for a very long time now. 530 000 MT of milled rice is the required consumption need of the Sierra Leonean population per annum. In 2007, national paddy rice production was projected at 638 000 MT. The level of rice self-sufficiency rose from 50.57% in 2002 to 62.15% in 2006 and then to 63.49% in 2007. The remainder must be imported at increasingly expensive prices in the current situation of high food prices, which includes rice. The price of rice has seen a steady increase in the entire country. What most affected by this, is the low-income urban and peri-urban households. The promotion of domestic rice production is therefore a key element in the strategies for improving rice self-sufficiency, stimulating economic growth and increasing rural income. Therefore, supporting rice production programme is the only solution to pull the country out of the worsening rice situation and maintain the present trend in rice self-sufficiency. Therefore, having an understanding of the strategic interventions in rice production in Sierra Leone is an important ingredient in the promotion and attainment of rice self-sufficiency. 展开更多
关键词 STRATEGY rice production self-sufficiency Sierra Leone
下载PDF
Empirical Analysis of Agricultural Policy Impacts of Senegal for food Self-sufficiency: The Stochastic Frontier Production of Rice and Maize in Senegal River Valley
7
作者 ARAME TOP KWANSOO KIM 《Journal of Statistical Science and Application》 2017年第3期104-113,共10页
The stochastic production function estimates of rice and maize in Senegal River Valley demonstrate the possibility to reach self-sufficiency of rice in Senegal. Nonetheless, its fulfillment requires many accompanying ... The stochastic production function estimates of rice and maize in Senegal River Valley demonstrate the possibility to reach self-sufficiency of rice in Senegal. Nonetheless, its fulfillment requires many accompanying measures in rice and maize production. These measures include all upstream and downstream activities related to agricultural production for their efficiency and sustainability in rice and maize production to maintain the country's comparative advantages and competitiveness. Then priorities should be given to agricultural infrastructure building, establishment of credit markets, and providing an easy access of production factors (e.g., improved land, fertilizers, improved and certified seeds, as well as agricultural machines). Furthermore, policy makers should provide a larger incentive in terms of producer price to encourage farmers to increase considerably their outputs, thereby farmers face smaller risk of having non-sold outputs. And during an early harvesting period, appropriate policy measures are in need to prevent farmers from dumping their products under severe social and economic pressures such as children schooling and loan payment, etc 展开更多
关键词 Agricultural policies Stochastic frontier production Food self-sufficiency Senegal River Valley
下载PDF
CHINA'S INDISPENSABLE WAY TO GRAIN SELF-SUFFICIENCY
8
作者 Lou Chenghou(Beijing University of Agriculture) 《Bulletin of the Chinese Academy of Sciences》 1997年第1期73-76,共4页
In China’s countryside today, so far the foodstuffs for daily-life subsistence are still taken from the traditional farming production in addition to the yield of animal husbandry, while crop plantation takes the lio... In China’s countryside today, so far the foodstuffs for daily-life subsistence are still taken from the traditional farming production in addition to the yield of animal husbandry, while crop plantation takes the lion’s share in our rural economy. During the Medieval Age of the Western countries, however, special stress was placed on raising livestock on pastureland until the Industrial Revolution occurred in the 18th century when grain-oriented agriculture came into being. As a result of the unprecedented boom of modern science and technology now sweeping the whole world, farming productivity has sky- 展开更多
关键词 CHINA’S INDISPENSABLE WAY TO GRAIN self-sufficiency
下载PDF
On-site solar PV generation and use: Self-consumption andself-sufficiency 被引量:1
9
作者 Zheng Wang Mark B.Luther +2 位作者 Peter Horan Jane Matthews Chunlu Liu 《Building Simulation》 SCIE EI CSCD 2023年第10期1835-1849,共15页
As energy storage systems are typically not installed with residential solar photovoltaic (PV) systems,any “excess” solar energy exceeding the house load remains unharvested or is exported to the grid.This paper int... As energy storage systems are typically not installed with residential solar photovoltaic (PV) systems,any “excess” solar energy exceeding the house load remains unharvested or is exported to the grid.This paper introduces an approach towards a system design for improved PV self-consumptionand self-sufficiency. As a result, a polyvalent heat pump, offering heating, cooling and domestic hotwater, is considered alongside water storage tanks and batteries. Our method of system analysisbegins with annual hourly thermal loads for heating and cooling a typical Australian house inGeelong, Victoria. These hourly heating and cooling loads are determined using Transient SystemSimulation (TRNSYS) software. The house’s annual hourly electricity consumption is analysed usingsmart meter data downloaded from the power supplier and PV generation data measured with aPV system controller. The results reveal that the proposed system could increase PV self-consumptionand self-sufficiency to 41.96% and 86.34%, respectively, resulting in the annual imported energybeing reduced by about 74%. The paper also provides sensitivity analyses for the hot and coldstorage tank sizes, the coefficient of performance of the heat pump, solar PV and battery sizes.After establishing the limits of thermal storage size, a significant impact on self-efficiency can berealised through battery storage. This study demonstrates the feasibility of using a polyvalent heatpump together with water storage tanks and, ultimately, batteries to increase PV self-consumptionand self-sufficiency. Future work will concentrate on determining a best-fit approach to systemsizing embedded within the TRNSYS simulation tool. 展开更多
关键词 solar photovoltaic polyvalent heat pump energy storage self-consumption self-sufficiency
原文传递
What Determines China's Grain Imports and Self-sufficiency? The Role of Rising Domestic Costs and Varying World Market Prices 被引量:7
10
作者 Wusheng Yu Tianxiang Li Jing Zhu 《China & World Economy》 SCIE 2019年第5期1-24,共24页
China s grain sectors have faced unprecedented challenges in recent years as the ever-increasing and historically high level of grain output has failed to reduce grain imports. On the contrary, high grain imports and ... China s grain sectors have faced unprecedented challenges in recent years as the ever-increasing and historically high level of grain output has failed to reduce grain imports. On the contrary, high grain imports and high domestic stock have accompanied historically high domestic output, a situation dubbed the "triple high" phenomenon in current policy discussion. This paper explores the role of widening domestic-world market price gaps in determining the triple high phenomenon.Unlike earlier studies that relied on production capacities, this paper argues that domestic production and demand (hence imports) are functions of domestic and world market prices and proposes an analytical framework to explicitly capture such price gaps under restricted trade linkages in general equilibrium. Following this approach, a set of price scenarios for the 2011-2020 period are constructed and simulated in a computable general equilibrium model. Results from the core scenarios, in which recent domestic and world market price trends are assumed to continue, suggest that further widening price gaps would substantially increase grain imports and reduce domestic output (by 60 million tons) and self-sufficiency ratios from base levels. In the alternative scenarios with larger (smaller) price gaps, we find higher (lower) imports and larger (smaller) decreases in domestic output and self-sufficiency ratios. Such results provide important policy implications as China's agricultural policy undergoes significant adjustment. 展开更多
关键词 computable general equilibrium model domestic-world market price GAPS food security GRAIN IMPORTS self-sufficiency ratio triple high
原文传递
Patterns and trends in grain self-sufficiency on the Tibetan Plateau during 1985–2016 被引量:2
11
作者 SHI Wenjiao LU Changhe +1 位作者 SHI Xiaoli CUI Jiaying 《Journal of Geographical Sciences》 SCIE CSCD 2020年第10期1590-1602,共13页
Capacity for grain self-sufficiency on the Tibetan Plateau(TP)is an important basis for ensuring social stability and regional sustainability.Thus,based on county-level statistical data for population,grain production... Capacity for grain self-sufficiency on the Tibetan Plateau(TP)is an important basis for ensuring social stability and regional sustainability.Thus,based on county-level statistical data for population,grain production and consumption,we analyzed patterns and trends in grain supply and demand at regional,provincial,and county levels on the TP between 1985 and 2016.We applied two indices to evaluate capacity for grain self-sufficiency and found that the regional average self-sufficiency rate increased quickly by 1.97%/a since 1989,reaching 173.03%on the plateau over the period between 2010 and 2016.This indicates that grain supply in this region is able to fully meet demand.In addition,all provinces apart from Xinjiang exhibited similar increasing trends,attaining grain self-sufficiency during 2010–2016.Furthermore,59%of counties attained grain self-sufficiency over this period,mainly distributed in southern Tibet,in the Sichuan-Tibet junction area,and in eastern Qinghai Province.A number of gaps in grain supply and demand occurred within the headwater regions of the Yangtze and Yellow rivers as well as on the Qiangtang Plateau.Grain self-sufficiency significantly increased over the study period in 36%of counties,mainly distributed in the agricultural areas of southeastern Tibet and in eastern Qinghai.Across the whole plateau,capacity for grain self-sufficiency substantially increased between 1985 and 2016,although serious spatial imbalances remain. 展开更多
关键词 Tibetan Plateau GRAIN county scale self-sufficiency spatiotemporal distribution
原文传递
Impacts of Cultivated Land Conversion on Environmental Sustainability and Grain Self-sufficiency in China 被引量:2
12
作者 Shuhao Tan 《China & World Economy》 SCIE 2008年第3期75-92,共18页
Using provincial data, the present paper examines the impact of cultivated land conversion on agriculture and the environment. It is found that the grain production center is gradually moving towards more fragile and ... Using provincial data, the present paper examines the impact of cultivated land conversion on agriculture and the environment. It is found that the grain production center is gradually moving towards more fragile and water scarce areas, putting more pressure on the environment. Land conversion caused large losses in ecosystem service values in the 1990s, but large scale ecological restoration programs have been implemented since 2000 to compensate for such losses. The ecological restoration programs are concentrated in regions with relatively low land productivity, whereas cultivated land conversion usually takes place in areas with relatively high land productivity. Newly-cultivated land, especially that in areas marginally suit for agricultural production, is likely to have much lower productivity levels than the original cultivated land. Because the stock of potentially cultivable land is almost exhausted, China's grain self-suffiency policy can only be maintained by preserving the available stock of arable land and increasing its productivity in a sustainable way. 展开更多
关键词 China cultivated land conversion environmental quality grain self-sufficiency land policy
原文传递
Irrigated agriculture for food self-sufficiency in the sub-Saharan African region
13
作者 Ransford Opoku Darko Junping Liu +2 位作者 Shouqi Yuan Livingstone K.Sam-Amoah Haofang Yan 《International Journal of Agricultural and Biological Engineering》 SCIE EI CAS 2020年第3期1-12,共12页
Increasing agricultural productivity in Africa will have important impacts not only on the agricultural sector but also can be a catalyst for industrialization through agro-processing.Irrigation,therefore,has a crucia... Increasing agricultural productivity in Africa will have important impacts not only on the agricultural sector but also can be a catalyst for industrialization through agro-processing.Irrigation,therefore,has a crucial role in enhancing food security and reducing hunger in the region.Numerous countries in Africa consider water and irrigation management as a key factor in improving their food security and ensuring access to drinking-water for their populations.Fortunately,there is evidence from a number of places on the continent where the adoption of efficient irrigation systems has led to higher productivity among smallholder farmers.While the appropriate interventions for the diverse agro-ecological zones of sub-Saharan Africa are known,adoption among smallholder farmers still remains a challenge.Digital technology opens the vast untapped potential for farmers,investors,and entrepreneurs to improve the efficiency of food production and consumption in Africa.From precision farming to an efficient food supply chain,technology could bring major economic,social,and environmental benefits.Increasing investment and involvement of the private sector is crucial for the up-scaling of irrigation technologies.Indeed,the sheer optimism across the startup ecosystem is that extreme hunger can be cured in Africa,in this generation,by significantly transforming the industry that employs most of its citizens.This paper draws on lessons from past trends in the irrigation industry and emphasizes on novel directions to ensure that farmers,as well as other stakeholders reap the benefits associated with improved technologies. 展开更多
关键词 food self-sufficiency irrigation development small-holder farms sub-Sahara Africa sustainability
原文传递
“Eternal Motion” as a “Form of Movement of a Special Nature” and the Main Condition for the Creation of the Universe
14
作者 Avas Khugaev Eugeniya Bibaeva 《Journal of Applied Mathematics and Physics》 2024年第6期2041-2068,共28页
The article hypothesizes that DE and DM (UCM) are a “Form of Motion of a Special Nature”, where “Form of Motion” means “Eternal Motion” as the power of dynamics of different levels and varying degrees of self-su... The article hypothesizes that DE and DM (UCM) are a “Form of Motion of a Special Nature”, where “Form of Motion” means “Eternal Motion” as the power of dynamics of different levels and varying degrees of self-sufficiency, and by “Special Nature”, gravitational and two other properties of matter, “tied” to the “Eternal Movement” and completely dependent on it. Carriers of key properties of a “Special Nature” have been established: “0”-DE particles and “3”-DM particles (UDM). The unity of their inherent “motionally-gravitational” properties and the peculiarity of the relationship between “motion” and “gravity” are revealed: the higher the intensity of “Eternal Motion”, the stronger the gravitational properties of matter are manifested (and vice versa). The relationship of “time” with the “vibration frequency” and the “mass” of photons with the “degree of bonding and deformation properties of the field” is shown. The maximum level of gravity has been determined, which allows Nature to successfully create the Universe: such a landmark is the proximity to the property of the Primary Source—the “pure graviton” of the OSP space, the most powerful “motionally-gravitational” particle of the Universe. The reasons for the emergence of such an identity of the gravitational properties of particles with the indicators of a “pure graviton” are established: for “0”-DE particles, this is the acquisition of the function of “freedom of movement”;for “3”-DM particles (UDM), the creation of a special structure—a “double field” (“Main” and “Small”). The presence in the “double field” of specific “tools” for the creation of the worlds of the Universe—gravitational “waves” gives rise to impulses (shocks) of varying intensity and shape. A list of functions performed by “waves” in the “Main” and “Small” fields has been compiled. The specific conditions for the formation of “UDM Streams”, their transformation into a “Vortex” and, under the influence of a powerful Initial Impulse (push), sending them to the “place” of the creation of galaxies, are shown. It is suggested that there is a “Cycle of Matter in Nature” in the closed structure of our Universe due to the “work” of “waves” and the functioning of special “factories” in the form of exotic space objects—Black holes. 展开更多
关键词 DE DM (UCM) Graviton Eternal motion Double Field of the Universe Motionally-Gravitational Particles Degree of self-sufficiency Main Field Small Field Gravitational Waves Primary Impulse Flows UDM Vortex Time Massive Photons Clumps of DM Movement of Galaxies Factories of Black Holes Circulation of Matter in Nature
下载PDF
Energy analyses for the energetically self-sufficient supercritical water oxidation process
15
作者 LIU Yan-yan ZHAN Shi-ping +4 位作者 WANG Jing-chang ZHU Bo CHEN Shu-hua LIU Xue- wu Li Zhi-yi 《Journal of Chemistry and Chemical Engineering》 2008年第4期62-70,共9页
One of the bottle-neck problems to the commercial development of supercritlcal water oxidation (SCWO) is high operation cost. In this study the condition to realize an energetically self-sufficient SCWO process is a... One of the bottle-neck problems to the commercial development of supercritlcal water oxidation (SCWO) is high operation cost. In this study the condition to realize an energetically self-sufficient SCWO process is analyzed. The reaction heat is recovered by means of Organic Rankine Circle. The process of SCWO for phenol is simulated with the Aspen Plus~ process simulator, and the results show that the influence of temperature on reaction heat is small at a constant pressure. It is reasonable to neglect the effect of temperature and to estimate the heat of reaction with average temperature when the temperature changes in a small range. The necessary condition to realize an energetically self-sufficient SCWO process is that the released energy is not less than consumed one. Whether a waste system with given chemical composition is energeticallyself-sufficient can be estimated by ^QR^QH 〉 W The thermodynamics analysis shows that energetically self-sufficient SCWO process with an Organic Rankine Cycle is a feasible technology for the recovery of SCWO reaction heat,and the energy balance point for phenol is 2wt%. 展开更多
关键词 SCWO reaction heat organic Rankine circle energetic self-sufficiency
下载PDF
Self-sufficient Cytochrome P450s and their potential applications in biotechnology 被引量:1
16
作者 Bekir Engin Eser Yan Zhang +1 位作者 Li Zong Zheng Guo 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2021年第2期121-135,共15页
Cytochrome P450s(CYPs)are ubiquitously found in all kingdoms of life,playing important role in various biosynthetic pathways as well as degradative pathways;accordingly find applications in a vast variety of areas fro... Cytochrome P450s(CYPs)are ubiquitously found in all kingdoms of life,playing important role in various biosynthetic pathways as well as degradative pathways;accordingly find applications in a vast variety of areas from organic synthesis and drug metabolite production to modification of biomaterials and bioremediation.Significantly,CYPs catalyze chemically challenging CAH and CAC activation reactions using a reactive high-valent iron-oxo intermediate generated upon dioxygen activation at their heme center,while the other oxygen atom is reduced to the level of water by electrons provided through a reductase partner protein.Self-sufficient CYPs,encoding their heme domain and reductase protein in a single polypeptide,facilitate increased catalytic efficiency and render a less complicated system to work with.The self-sufficient CYP enzyme from CYP102A family(CYP102A1,BM3)is among the earliest and most-investigated model enzymes for mechanistic and structural studies as well as for biotechnological applications.An increasing number of self-sufficient CYPs from the same CYP102 family and from other families have also been reported in last decade.In this review,we introduce chemistry and biology of CYPs,followed by an overview of the characteristics of self-sufficient CYPs and representative reactions.Enzyme engineering efforts leading to novel self-sufficient CYP variants that can catalyze synthetically useful natural and non-natural(nature-mimicking)reactions are highlighted.Lastly,the strategy and efforts that aim to circumvent the challenges for improved thermostability,regio-and enantioselectivity,and total turnover number;associated with practical use of self-sufficient CYPs are reviewed. 展开更多
关键词 BIOCATALYSIS Heme enzymes CAH activation Cytochrome P450s self-sufficient P450s P450 BM3
下载PDF
Modeling the effects of urbanization on grain production and consumption in China 被引量:3
17
作者 LU Wen-cong Chen Ning-lu Qian Wen-xin 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2017年第6期1393-1405,共13页
The impact of rapid urbanization on food security of China has received considerable attention.It is not clear whether China can strike a balance between urbanization and food security,especially grain security.There ... The impact of rapid urbanization on food security of China has received considerable attention.It is not clear whether China can strike a balance between urbanization and food security,especially grain security.There have been numerous studies examining the effects of urbanization on grain production or consumption,but few studies have yet analyzed grain balances.Based on the Chinese World Agricultural Regional Market Equilibrium Model(CWARMEM),this paper explores the impacts of urbanization on national and regional grain balances through different scenarios.The CWARMEM is a global partial equilibrium multimarket model which captures the differences between urban and rural residents as well as the effects of globalization.The results show that urbanization has a small negative effect on maintaining grain self-sufficiency.Despite of that,China is able to achieve the objective of grain security set by its policymakers.Moreover,urbanization changes regional grain balances across China:The position of Northeast China and North China,as two dominant grain suppliers of China,will be weaken;Central China and East China will increase dependence on other grain suppliers;the grain surplus of Northwest China will increase slightly.Besides,in terms of grain category,urbanization helps China achieve self-sufficiency in food grain(rice and wheat),while expands deficit of feed grain(maize). 展开更多
关键词 URBANIZATION grain self-sufficiency grain security
下载PDF
China’s Food Security Status:Assessment and Strategic Reflections 被引量:1
18
作者 张元红 刘长全 国鲁来 《China Economist》 2015年第6期28-43,共16页
Based on an internationally recognized concept of food security, this paper has created a system of eight indicators to analyze China's food security. For the proper control and analysis of this study, the authors of... Based on an internationally recognized concept of food security, this paper has created a system of eight indicators to analyze China's food security. For the proper control and analysis of this study, the authors of this paper have chosen these indicators: supply, distribution, consumption, utilization efficiency, food security results, stability, sustainability and controllability. Results indicate that China's food security is currently at a high level and has been increasing in recent years. China's food security has multiple advantages with various indicators that include a self-sufficiency ratio, per capita calorie intake and protein supply that are above world average levels, even exceeding the average level of some developed countries. Major challenges facing China's food security include an unreasonable nutrition structure and poor environmental sustainability. In order to increase China's food security level, efforts must be made to adjust output structure, adopt an environmentally friendly pattern of production, attach importance to demand management, reduce unreasonable consumption and loss and moderately lower China's food reserve ratio. 展开更多
关键词 food security index self-sufficiency ratio SUSTAINABILITY
下载PDF
Energy Assessment of Building Integrated Photovoltaics and Fuel Cell Systems: Design Study for Building(s) of Mie, Japan
19
作者 Akira Nishimura Satoshi Kitagawa +1 位作者 Masafumi Hirota Mohan Lal Kolhe 《Smart Grid and Renewable Energy》 2017年第5期129-144,共16页
A building integrated energy system (photovoltaic (PV) and fuel cell (FC)) is proposed for assessment of the energy self-sufficiency rate in five cities of Mie prefecture in Japan. In this work, it is considered that ... A building integrated energy system (photovoltaic (PV) and fuel cell (FC)) is proposed for assessment of the energy self-sufficiency rate in five cities of Mie prefecture in Japan. In this work, it is considered that the electricity requirement of the building is provided by the building integrated photovoltaic (BIPV) system and the gap between the energy demand and BIPV supply is fulfilled by the FC. The FC is powered by the electrolytic H2 produced from the surplus power of PV. A design study of using the proposed system in five cities in Mie prefecture, which are in center part of Japan, has been performed. It has been observed that the monthly power production from BIPV is higher in spring and summer, while it is lower in autumn and winter at all considered locations. The self-sufficiency rate of the FC system is higher with decreasing households’ number and it has been observed that the 12 households are more suitable for full cover of the electricity demand by the combined system of PV and FC. The relationship between the households’ number and self-sufficiency rate of the FC system per solar PV installation area can be expressed by exponential curve. The coefficient of the exponential curve can predict the suitable city for the BIPV system with FC system utilizing electrolytic H2 generated by using excess energy from the PV system. 展开更多
关键词 Smart BUILDING Photovoltaics H2 PRODUCED by Water ELECTROLYSIS Fuel Cell self-sufficiency Rate
下载PDF
The Developmental Stages of Rice (Bap) Culture in Korea: From Food Insufficiency towards Trade Dependency
20
作者 Kim Bok-rae 《Journal of Food Science and Engineering》 2018年第1期20-34,共15页
The aim of this paper is to examine the developmental stages of rice culture in Korea. It is divided into five sections: (1) first stage (Japanese colonial period-1959): absolute food insufficiency, (2) second... The aim of this paper is to examine the developmental stages of rice culture in Korea. It is divided into five sections: (1) first stage (Japanese colonial period-1959): absolute food insufficiency, (2) second stage (1960s): encouraging the use of flour & rice with mixed grains for food, (3) third stage (1970s): rice self-sufficiency, (4) fourth stage (1980s): change of rice culture, (5) fitch stage (since1990s): stabilization/stagnation of rice culture in the era of globalization. 展开更多
关键词 Rice culture food insufficiency rice self-sufficiency industrialization of rice globalization.
下载PDF
上一页 1 2 下一页 到第
使用帮助 返回顶部