oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2019 ( 897 )

2018 ( 20503 )

2017 ( 21338 )

2016 ( 23891 )

Custom range...

Search Results: 1 - 10 of 304271 matches for " Fertilizer demand<br>人口 "
All listed articles are free for downloading (OA Articles)
Page 1 /304271
Display every page Item
An Analysis on Driving Force of Fertilizer Demand of China Ⅲ Population, Economy, Technology and Policy
中国化肥消费需求影响因素及走势分析Ⅲ人口、经济、技术、政策

ZHANG Wei-feng,JI Yue-xiu,MA Ji,WANG Yan-feng,MA Wen-qi,ZHANG Fu-suo,
张卫峰
,季玥秀,马骥,王雁峰,马文奇,张福锁

资源科学 , 2008,
Abstract: 从人口、国民经济、农业经济、生产技术及政策角度分析了中国及世界上一些典型国家化肥消费和这些因素的关系。从化肥消费强度和消费系数角度深入分析了各个国家发展的特点。结果表明世界主要国家化肥消费都随人口增长速率的增加而增长,反映出人民基本粮食和营养需求对化肥需求具有促进作用。同时随着国民经济发展,化肥应用领域已经扩展到化工、渔业、林业、牧业等多个领域,我国传统农田使用比例已下降到85%。各个国家农业经济发展中的化肥养分资源利用效率差异巨大,发达国家已走上集约化可持续发展的道路,每万元农业GDP的化肥消费已降至lt纯养分,而发展中国家尤其是中国的强度仍高于2t纯养分,且磷肥和钾肥的需求还在增长。从弹性系数来看,我国农业经济发展与化肥需求仍呈等比例增长关系,说明农业经济对化肥过度依赖,其原因是技术发展较慢,单位养分的生产力水平和整个国家的养分再利用水平太低。但从欧美的经验来看,中国提高技术水平、转变资源利用效率的空间很大,而且在不长的时期内完全有可能实现,但取决于政策因素的转变。
Demand and Supply Balance of Fertilizer Resources in China Based on Agricultural Crop Demand (Ⅰ) --Nitrogen Fertilizer Resources
基于农作物需求的中国化肥资源供求平衡研究(Ⅰ)

LIU Ai-min,FENG Zhi-ming,YU Ge,
刘爱民
,封志明,于格

资源科学 , 2005,
Abstract: 化肥是一种重要的农业资源,氮肥是最重要的化肥资源品种.供给和需求是化肥资源供求动态平衡的两个方面,影响供给的主要因素有国内生产和进出口;影响需求的主要因素有不同地区农作物类型、不同农作物的种植面积和不同农作物对不同化肥品种的施用量.本文在分析影响化肥供求平衡因素的基础上,对尿素和碳铵等主要氮肥品种的供求平衡问题进行了重点研究,并建立了分省的尿素供求平衡表.研究结果显示,尿素的氮肥供给量占中国氮肥供给总量的55.0%左右;而碳铵的氮肥供给量占中国氮肥供给总量的比例已有1995年的38、7%,下降到2003年的23.0%左右.另外,单一氮肥品种的氮肥供给量占氮肥供给总量的比例由1995年的96.2%,减少到2003年的87.0%.目前我国尿素供过于求,而碳铵供求基本平衡.
Global nitrogen fertilizer supply and demand outlook
Michel Prud’homme
Science China Life Sciences , 2005, DOI: 10.1007/BF03187121
Abstract: This paper presents a brief overview of the world nitrogen fertilizer demand, highlights trends in the global and regional developments of production capacity and provides a medium-term perspective of the global nitrogen supply/demand balance.
Review and Discussion on the Components of "Proper Population"
"适度人口"的分野与述评

YUAN Hua,rong,
原华荣

浙江大学学报(人文社会科学版) , 2002,
Abstract: Proper Population" is composed of two major schools with opposing objectives, viewpoints and theoretical frameworks. "Economically Proper Population" seeks "maximum output" and is founded on the premise of "demand creates supply" and the transformation of technologies, and achieving unlimited economic growth and "the maximum benefits for the majority population" through proper population growth, maintenance of "effective demand" and overcoming resource limitations. But the limited nature of resources will undoubtedly erode its foundation. Believing that natural resources are limited and that "supply determines demand", "Environmentally Proper Population" strives for the balance of population and environment. It aims at the harmony between mankind and nature through "double zero growth" and therefore restricts population and economic scale within the limits of nature. However, this balance between population and environment, orchestrated by mankind itself, has destructive impacts on both the ecological system and mankind itself. It has therefore presented serious challenges to its objective of balance.
Determinantes da demanda de fertilizantes no Brasil no período de 1970 a 2002
Nicolella, Alexandre Chibebe;Dragone, Diogo S.;Bacha, Carlos José Caetano;
Revista de Economia e Sociologia Rural , 2005, DOI: 10.1590/S0103-20032005000100005
Abstract: this paper estimates an equation for fertilizer demand in brazil, considering the time period from 1970 to 2002. co-integration analysis procedures have been used and they show that just the level model (lso method), valid for long term, presents good econometrics results. fertilizer demand is inelastic to both price fluctuations and rural credit supplied. these results are consistent with the international estimates and they also confirm the importance of fertilizer as an input for the brazilian agriculture.
POPULATION, FOOD AND THE UTILIZATION OF LAND AND WATER RESOURCES OF NINGXIA HUI AUTONOMOUS REGION
宁夏人口,粮食与水土资源利用

Su Renqiong Ni Jianhua,
苏人琼
,倪建华

自然资源学报 , 1989,
Abstract: Population, food and the utilization of water and land resources are important problems in the economic development of Ningxia Hui Autonomous Region. This paper analyses the present situation of these problems and by applying the Grey System Theory and regressive analysis, bulids a forecasting model of population and food. According to the model, a prediction of the population and food of the region in 2000 has been made. After making a balance analysis between supply and demand of food under Various conditions of the water and land resources in 2000, it points out that the region'sfood production would be able not only to be-self-sufficient but also to provide a certain amount of marketable grain, if we fully utilize the water resource of the Yellow River, enlargel the irrigated land areas, and adopt new farming technigues. At the end of the paper, the main ways to solve the problems of food and to prevent the deterioration of ecosystem and environment have been suggested.
Evaluation of China''s Potassium Fertilizer Market based on Welfare Maximization
基于经济福利最大化理论的中国钾肥资源市场评价

WU Yong-jiao,MA Hai-zhou,DONG Suo-cheng,
吴永娇
,马海洲,董锁成

资源科学 , 2008,
Abstract: 考察钾肥资源供求关系的演变对农业可持续发展的研究有着重要的意义。本研究旨在引入经济福利最大化理论对我国钾肥资源市场有效性进行评价,以揭示我国钾肥资源市场供求关系的演化规律,为优化钾肥资源市场和促进农业可持续发展提供可靠的理论依据。首先,对我国不同时期的钾肥资源市场(1998年以前,1998~2006)进行了有效性的综合评价;其次,对钾肥资源市场供求进行预测模拟分析(2006年以后);最后,基于模拟分析的基础上提出优化我国钾肥资源市场的对策和建议。研究结果表明: 1998年以前,钾肥资源市场受计划经济体制的强烈影响,政府直接制定钾肥资源产量和价格,钾肥资源价格跟产量成复杂关系,钾肥资源市场配置资源低效;1998~2006年期间,市场机制调节着钾肥资源市场,但市场机制不够完善,钾肥价格跟产量成正相关关系,钾肥资源市场仍处于较低效资源配置状态;2006年以后,市场机制日趋完善,市场配置资源更为有效, 预计钾肥资源需求在2010年将达1 096×104t(K2O)。
Biodigest?o anaeróbia de efluente de abatedouro avícola
Oliveira, Arley Borges de Morais;Orrico, Ana Carolina Amorim;Orrico Júnior, Marco Antonio Previdelli;Sunada, Natalia da Silva;Centurion, Stanley Ribeiro;
Revista Ceres , 2011, DOI: 10.1590/S0034-737X2011000600003
Abstract: the objective of this study was to evaluate the process of anaerobic digestion treatment of poultry slaughterhouse wastewater, considering hydraulic retention time (hrt) of 7, 14 and 21 days, plus the addition of lipolytic enzyme to the substrates at concentrations of 0; 0.5; 1.0 and 1.5 g l-1 charge added to the digesters. the influence of hrt and the addition of lipolytic enzyme to the substrates was evaluated by biogas production and ch4 production potentials for cod (chemical oxygen demand) added and removed as well as by reductions in the levels of cod, concentrations of n, p and k and ph values. the results showed that there was influence of hrt (hrt 7 in which the expressed best results, average weekly production of biogas with 40.7 l-1 and 32.2 l-1 ch4) and concentrations of enzymes with higher production values to treatments 1.0 (24.6 l) and 1.5 g l-1 (26.2 l), which did not differ. the enzyme concentrations of 1.0 and 1.5 g l-1 showed the largest potential for biogas production (1.1 and 1.1 g l-1 of cod added, respectively) and methane (0.9 and 0.8 g1 l cod added, respectively), compared with 0.5 g l-1 (0.8 and 0.7 g l-1 biogas and ch4 respectively) and 0 g l-1 (0.7 and 0.5 g l-1 biogas and ch 4, respectively). the highest cod removals were achieved at concentrations of 0.5 g l-1 (83.3%) and hrt of 21 days (74.4%). however for there to be a more efficient energy recycling, it is recommended to use concentrations of 1.0 g l-1 effluent and hydraulic retention time of seven days.
A study on relationship of conservation and tourism demand of world heritage sites in China
中国世界遗产地保护与旅游需求关系

WU Bi-hu,LI Mi-mi,HUANG Guo-ping,
吴必虎
,李咪咪,黄国平

地理研究 , 2002,
Abstract: It has been recognized for long time that there exists conflict between heritage protection and tourism development, especially in those developing countries where local governments appealed more on economic benefits from heritage tourism. Since China adopted the Convention Concerning the Protection of the World Culture and Natural Heritage in 1985, 21 cultural heritages, 3 natural heritages and 4 mixed heritages have been inscribed in the list. Considering the fast development of heritage tourism in China, academic research literature is still less than hoped. What readers could find in this paper is a special relationship between demands on tourism development and need to protect World Heritage Sites (WHSs) in the country. To observe the conflict between the two sides, a comprehensive investigation and study is done with technical support of GIS, quantitative geography and other geographical analysis methods. According to the results of the research, there are many forces that enhance heritage tourism development in this most rapidly growing country of Asia, including densely populated urban market versus limited number of WHSs; closer distance between population centers and WHSs (easy access from major tourism market to WHSs); being at a special stage of industrial transforming of the country (switching from secondary industry to tertiary industry and service-oriented industry); more preferences of potential domestic tourism market; and being in a shortage of financial resources for heritage protection. Therefore, tourism development of WHSs is a natural result in current economic and social situation. Meanwhile, findings of the analysis also demonstrate that heritage protection is the most important consideration while taking them as major tourism attractions, because heavy pressure of tourism development calls for more efforts to preserve those sites. Only a well-balanceddevelopment model could maintain a sustainable development of WHSs and secure the long-term benefits.
Fertilizer Relevant Legislation in Japan, South Korea, and Taiwan District and Their Enlightenment to China's Fertilizer Management
日本、韩国、台湾地区肥料相关的立法及其对我国肥料管理的启示

SHEN Ren-fang,LIANG Lin-zhou,ZHAO Xue-qiang,
沈仁芳
,梁林洲,赵学强

土壤 , 2012,
Abstract: Based on a brief introduction of the fertilizer legislative profiles in Japan, South Korea, Taiwan district and other countries, the status, necessity and urgency of China's fertilizer legislation were analyzed. It tries to provide a basis for fertilizer legislation in China.
Page 1 /304271
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.