中国铝物质流历史变化分析和再生铝资源利用研究     

刘艳飞  李颖  林子芃  刘仟策  韩中奎 《地球学报》2023,44(2):333-340

本文采用物质流分析(Material Flow Analysis, MFA)的方法, 构建了铝全生命周期动态物质流分析框架, 自上而下的追踪了1949—2021年中国铝的流量、存量和供需情况。结果表明: 1)1949—2021年中国铝土矿铝物质累计流入量5.86亿t, 国内开采与进口各占一半左右。实际铝物质累计消费量3.74亿t。生命周期内铝损失严重, 铝物质损失量2.39亿t。2)2021年人均铝物质社会存量208.9 kg/人, 与同经济发展时期的北美、日本基本一致。3)1990年以来中国再生铝产量快速增长, 累计0.77亿t, 以国内生产为主, 占比76.7%。随着含铝产品到达寿命及未来铝需求量的持续走高, 将迎来含铝产品的报废时代。建议从全生命周期的角度出发, 减少铝在各个环节的损失量; 合理布局再生铝产业, 提高再生铝的利用, 优化铝供应结构, 促进铝工业低碳转型, 支撑“双碳”目标的实现。  相似文献   

Carbon stock of oil palm plantations and tropical forests in Malaysia: A review          下载免费PDF全文

Lip Khoon Kho  Martin Rudbeck Jepsen 《Singapore journal of tropical geography》2015,36(2):249-266

In Malaysia, the main land change process is the establishment of oil palm plantations on logged‐over forests and areas used for shifting cultivation, which is the traditional farming system. While standing carbon stocks of old‐growth forest have been the focus of many studies, this is less the case for Malaysian fallow systems and oil palm plantations. Here, we collate and analyse Malaysian datasets on total carbon stocks for both above‐ and below‐ground biomass. We review the current knowledge on standing carbon stocks of 1) different forest ecosystems, 2) areas subject to shifting cultivation (fallow forests) and 3) oil palm plantations. The forest ecosystems are classified by successional stage and edaphic conditions and represent samples along a forest succession continuum spanning pioneer species in shifting cultivation fallows to climax vegetation in old‐growth forests. Total carbon stocks in tropical forests range from 4 to 384 Mg C/ha, significantly wider than the range of total carbon stocks of oil palm plantations, 2 to 60 Mg C/ha. Conversion of old‐growth forest areas to oil palm plantations leads to substantial reduction in carbon storage, while conversion of forest fallows to oil palm plantations may sustain or even increase the standing carbon stock.  相似文献   

Modeling demand/supply of water resources in the arid region of northwestern China during the late 1980s to 2010     

LIU Xingran  SHEN Yanjun  GUO Ying  LI Shuo  GUO Bin 《地理学报(英文版)》2015,25(5)

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Developing country perspectives on ‘mitigation actions’, ‘NAMAs’, and ‘LCDS’     

Emily Tyler  Anya Boyd  Kim Coetzee  Marta Torres Gunfaus  Harald Winkler 《Climate Policy》2013,13(6):770-776

The MAPS programme, which seeks to deepen mitigation ambition in developing countries, is engaged in exploring the concepts of Nationally Appropriate Mitigation Actions (NAMAs) and Low Carbon Development Strategies (LCDS) from a developing country perspective. Here, climate mitigation practitioners in six developing countries were surveyed for their understanding of these concepts (anonymous, personal communications with climate mitigation practitioners in Argentina, Brazil, Chile, Colombia, India, and South Africa). It is found that there is much scope for clarity and conceptual elaboration in this policy space. NAMAs are largely interpreted as mitigation activities packaged for submission to the United Nations Framework Convention on Climate Change (UNFCCC) registry, but are not held to constitute the full set of mitigation activity in a developing country. New terminology may be needed to describe this broader set. A tighter interpretation of LCDS to distinguish between a strategic or coordinating policy action may be useful. Other themes arising include the way ‘national appropriateness’ is reflected in the concepts, and the role of international policy in deepening mitigation action in developing countries.  相似文献   

Top-down and bottom-up modelling to support low-carbon scenarios: climate policy implications     

Patricia Fortes  Sofia Simões  Júlia Seixas  Denise Van Regemorter  Francisco Ferreira 《Climate Policy》2013,13(3):285-304

Bottom-up and top-down models are used to support climate policies, to identify the options required to meet GHG abatement targets and to evaluate their economic impact. Some studies have shown that the GHG mitigation options provided by economic top-down and technological bottom-up models tend to vary. One reason for this is that these models tend to use different baseline scenarios. The bottom-up TIMES_PT and the top-down computable general equilibrium GEM-E3_PT models are examined using a common baseline scenario to calibrate them, and the extend of their different mitigation options and its relevant to domestic policy making are assessed. Three low-carbon scenarios for Portugal until 2050 are generated, each with different GHG reduction targets. Both models suggest close mitigation options and locate the largest mitigation potential to energy supply. However, the models suggest different mitigation options for the end-use sectors: GEM-E3_PT focuses more on energy efficiency, while TIMES_PT relies on decrease carbon intensity due to a shift to electricity. Although a common baseline scenario cannot be ignored, the models’ inherent characteristics are the main factor for the different outcomes, thereby highlighting different mitigation options.

Policy relevance

The relevance of modelling tools used to support the design of domestic climate policies is assessed by evaluating the mitigation options suggested by a bottom-up and a top-down model. The different outcomes of each model are significant for climate policy design since each suggest different mitigation options like end-use energy efficiency and the promotion of low-carbon technologies. Policy makers should carefully select the modelling tool used to support their policies. The specific modelling structures of each model make them more appropriate to address certain policy questions than others. Using both modelling approaches for policy support can therefore bring added value and result in more robust climate policy design. Although the results are specific for Portugal, the insights provided by the analysis of both models can be extended to, and used in the climate policy decisions of, other countries.  相似文献   

储良广眼砧穗不亲和问题研究     

洪家胜  王育林 《广东海洋大学学报》1997,(1)

储良广眼的砧穗不亲和现象在众多个体中呈现从亲和至不亲和的连续变化，随砧、穗周长差异的增大，不亲和症状表现突出。砧、穗周长比值与几个生长量指标存在显著相关。提出以砧／穗比作为衡量不亲和程度指标。靠接加砧结果表明对严重不亲和树出现的症状有较大的缓解。  相似文献   

南海区多鱼种声学评估工作程序   总被引：3，自引：0，他引：3  

李永振  陈国宝  孙典荣  张旭丰 《广东海洋大学学报》2003,23(1):35-40

总结了利用SimradEK50 0声学系统进行了南海区多鱼种资源评估经验 ,介绍了多鱼种声学评估的工作流程 ,包括调查方案制定、声学数据采集、映像分析、积分值分配、资源量的计算方法等关键过程 ,同时及在工作中应该注意的细节。  相似文献   

温泉县气候变化对农牧业生产的影响     

陈万江  张海军 《沙漠与绿洲气象(新疆气象)》2008,2(3):52-54

分析了温泉县历年来基本气候要素的变化,发现本地有着变暖、增湿、平均风速减小等变化趋势,结合对本地农牧业生产的影响提出一些启示。  相似文献   

高速公路、市场潜力与人力资本空间分布研究     

梁爽  张燕华 《地域研究与开发》2021,40(1):34-39

基于我国2000年、2010年250个城市数据,通过高速公路网测算城市间时间距离以刻画城市的国内和国外市场潜力,控制城市教育水平、内部市场规模、产业结构、行政级别等。考虑空间自相关,采用空间计量模型研究不同空间尺度市场潜力对人力资本空间分布的差异化影响。结果发现:高速公路网的基本建成使得市场潜力显著影响城市的人力资本积累,城市越靠近国内市场中心则人力资本水平越低,越靠近国外市场则人力资本水平越高。考虑规模效应和竞争效应布局城市交通网络,加强教育投入,能够有效提高城市人力资本水平。  相似文献   

Global city and precarious work of migrants in China: a survey of seven cities     

Zhongwei Sun 《Urban geography》2017,38(10):1479-1496

Drawing on data from a sample of 2,518 migrant workers from seven cities in China, this paper examines how precarious work of migrants varies across different types of cities. The research finds that compared with their counterparts in the non-global cities, migrant workers in Shanghai experience lower levels of precarity in their jobs. Additionally, with regards to different aspects of precariousness of work, Shanghai performs particularly better on providing labor contracts and social insurances. Contrary to the standard “Global City” hypothesis, it seems that in a developing country such as China, globalization is more likely to improve the institutionalization and standardization of industrial relationships rather than decay them.  相似文献