Heavy Metal Concentrations in Rice from Guangzhou and Associated Health Risks   总被引：1，自引：1，他引：0  

CHEN Nengchang  ZHANG Xiaoxia  ZHENG Yuji 《资源与生态学报(英文版)》2018,9(1):85-91

In recent years, excessive levels of cadmium (Cd) in rice have been a focus of attention of the government, the public and scientists. In Guangzhou rice is a staple food for most citizens and understanding the level of Cd and other heavy metals in rice is important for food safety and health. Consumers in different income groups purchase rice from various sources at different prices but we know little about the relationship between price and safety. At the same time, the presence of zinc (Zn) can also affect the level of risk from Cd in rice and so affect food safety. This study offers a preliminary exploration of interactions between price, safety and nutritional quality. 125 rice samples were collected from markets and from the homes of high-income, middle-income and low-income groups in Guangzhou city, and were tested for the content of Cd and Zn. The results showed that 25.6% of the rice samples contained Cd in excess of the national standard, with higher levels of Cd in Indica rice than in Japonica. At the same time, we designed a questionnaire survey for groups with different incomes to assess their exposure to risks from rice with Cd and their perceptions and sources of information about risks. The survey showed that, as a whole, the low-income group faces higher risks from rice with Cd, and that there is strong public demand for scientific information about Cd in rice.  相似文献   

The poverty dynamics in rural China during 2000–2014: A multi-scale analysis based on the poverty gap index     

Qiang Ren  Qingxu Huang  Chunyang He  Mengzhao Tu  Xiaoying Liang 《地理学报(英文版)》2018,28(10):1427-1443

As the largest developing country in the world, China’s rural areas face many poverty- related issues. It is imperative to assess poverty dynamics in a timely and effective manner in China’s rural areas. Therefore, we used the poverty gap index to investigate the poverty dynamics in China’s rural areas during 2000–2014 at the national, contiguous poor areas with particular difficulties and county scales. We found that China made significant achievements in poverty alleviation during 2000–2014. At the national scale, the number of impoverished counties decreased by 1428, a reduction of 97.28%. The rural population in impoverished counties decreased by 493.94 million people or 98.76%. Poverty alleviation was closely associated with economic development, especially with industrial development. Among all 15 socioeconomic indicators, the industrial added value had the highest correlation coefficient with the poverty gap index (r = –0.458, p<0.01). Meanwhile, the inequality of income distribution in the out-of-poverty counties has been aggravated. The urban-rural income gap among the out-of-poverty counties increased by 1.67-fold, and the coefficient of variation in rural per-capita income among the out-of-poverty counties also increased by 9.09%. Thus, we argued that special attention should be paid to reducing income inequality for sustainable development in China’s rural areas.  相似文献   

Assessment and determinants of per capita household CO<Subscript>2</Subscript> emissions (PHCEs) based on capital city level in China     

Lina Liu  Jiansheng Qu  Zhiqiang Zhang  Jingjing Zeng  Jinping Wang  Liping Dong  Huijuan Pei  Qin Liao 《地理学报(英文版)》2018,28(10):1467-1484

Household CO₂ emissions were increasing due to rapid economic growth and different household lifestyle. We assessed per capita household CO₂ emissions (PHCEs) based on different household consuming demands (including clothing, food, residence, transportation and service) by using provincial capital city level survey data in China. The results showed that: (1) there was a declining trend moving from eastward to westward as well as moving from northward to southward in the distribution of PHCEs. (2) PHCEs from residence demand were the largest which accounted for 44% of the total. (3) Correlation analysis and spatial analysis (Spatial Lag Model (SLM) and Spatial Error Model (SEM)) were used to evaluate the complex determinants of PHCEs. Per capita income (PI) and household size (HS) were analyzed as the key influencing factors. We concluded that PHCEs would increase by 0.2951% and decrease by 0.5114% for every 1% increase in PI and HS, respectively. According to the results, policy-makers should consider household consuming demand, income disparity and household size on the variations of PHCEs. The urgency was to improve technology and change household consuming lifestyle to reduce PHCEs.  相似文献   

经济发展对城市宜居性的影响——基于中国40个大中城市的实证分析     

王毅  苗转莹  陆玉麒  朱英明 《地理学报》2022,77(10):2529-2546

在中国经济和城镇化都逐步迈入高质量发展阶段的背景下,厘清经济发展对城市宜居性的影响规律具有重要的学术价值和应用价值。本文将宜居性作为一项“要素”引入生产函数研究框架,构建了经济发展对城市宜居性影响的理论模型,并基于2005—2019年中国40个大中城市的面板数据,利用系统GMM、面板门槛模型等方法对其进行实证检验。结果表明：① 2005—2019年中国大中城市的宜居性水平总体呈上升态势,但存在明显的维度分异和空间分异特征。② 总体上经济发展对城市宜居性的提高具有抑制效应,但这种效应在不同时间阶段和不同城市规模中呈现出明显的异质性。对于进入经济新常态阶段前,以及规模较大的直辖市和部分经济发达的省会城市,这种抑制作用比较显著;而进入新常态阶段后,经济发展对城市宜居性提升具有明显的促进作用。③ 经济发展对城市宜居性的影响还存在门槛效应,随着居民收入水平的提高,其影响效应呈现出显著的倒“N”型门槛特征。当经济发展使职工平均工资处于6万元至8万元时,经济发展能明显提高城市宜居度。经济发展本身对城市宜居性的影响表现出显著的单一门槛抑制效应,但其负向影响呈现出边际效率递减规律。最后,根据本文的研究发现从“宏观指引”和“微观行动”两个层面提出相应的政策启示。  相似文献   

电子商务网站成本及收入分析   总被引：4，自引：0，他引：4  

周斌  蔡久忠 《成都信息工程学院学报》2002,17(3):206-209

在网站建设与运行过程中所发生的资金耗费即是网站成本。在这里，着重讨论电子商务网站成本的分类，各类成本的构成、特征，网络收入的来源，进而提出了判别能否持续经营电子商务网站的条件。  相似文献   

Impact of regional development on carbon emission: Empirical evidence across countries   总被引：1，自引：1，他引：0  

Guoping Li  Yuan Yuan 《中国地理科学(英文版)》2014,24(5):499-510

Global warming is recently an urgent issue worldwide. The increase of carbon emissions induced by human economic activi- ties has become a major driving force behind global climate change. Thus, as a matter of social responsibility, reasonable carbon con- straints should be implemented to ensure environmental security and sustainable development for every country. Based on a summary of studies that examined the relationship between carbon emissions and regional development, this paper shows that human activity-led carbon emission is caused by the combination of several influencing factors, including population size, income level, and technical pro- gress. Thus, a quantitative model derived from IPAT-ImPACT-Kaya series and STIRPAT models was established. Empirical analysis using multivariate nonlinear regression demonstrated that the origins of growing global carbon emission included the increasing influ- encing elasticity of the population size and the declining negative effect of technical progress. Meanwhile, in context of classification of country groups at different income levels, according to the comparison of fluctuating patterns of the influencing elasticity, technical progress was found as the main factor influencing carbon emission levels in high-income countries, and population size might he the controlling factor in middle-income countries. However, for low-income countries, the nonlinear relationship between carbon emission and its influencing factors was not significant, whereas population growth was identified as an important potential driving force in future carbon emissions. This study can therefore provide a reference for the formulation of policies on carbon constraints, especially to de- velop more efficient carbon mitigating policies for countries at different income levels.  相似文献   

Impact of farmer households’livelihood assets on their options of economic compensation patterns for cultivated land protection     

LI Guangdong  FANG Chuanglin  QIU Daochi  WANG Liping 《地理学报》2014,24(2):331-348

With rapid urbanization and the socio-economic transformation,cultivated land protection has gradually become a major concern in China. The economic compensation plays a crucial role in promoting cultivated land protection and improving the utilization ratio of cultivated land. Farmer household's satisfaction has a great influence on the effectiveness of compensation. Therefore,households' willingness to select the economic compensation pattern for cultivated land protection has been considered and re-examined. By employing Participatory Rural Appraisal method (PRA),3 villages and 392 households were investigated and sampled in mesa and hilly areas of Chongqing. Then a quantitative analysis framework of household livelihood hexagon has been developed to quantify the livelihood assets of different farmer households. Finally,the Gray Relation Model and Probit Regression Model have been employed to explore the coupling relationship between the household livelihood assets and their compensation pattern options. The results show that there are both qualitative and spatial heterogeneity in household livelihood assets. We found that the inequality of livelihood assets is evident for five household types. There is a spatial trend that the higher the elevation,the less livelihood assets are. In addition,their options of economic compensation pattern vary from Chengdu Pattern to Foshan Pattern due to their difference in livelihood assets and difference in location. In detail,there is a coupling relationship between household livelihood assets and their compensation pattern;negative correlation is observed between natural assets value and household pattern options,while the other livelihood assets have positive impacts on compensation pattern in varying degrees,which from the top are psychological assets,human assets,physical assets,financial assets,and social assets respectively. A conceptual compensation pattern system has been designed to meet the demands for farmer households mainly according to their shortage in livelihood assets. In addition,compensation method,compensation standard,the basis of compensation and the source of compensation funds have been proposed accordingly.  相似文献   

青海高原西宁城镇社区家庭能耗直接碳排放研究     

姜璐  丁博文鹏  周学伟  胡小康  史培军 《地理科学》2023,43(1):119-129

选取青海高原城市西宁为研究对象,开展家庭能源消费问卷入户调查,建立高原城市家庭能源消费数据库(N=500),采用探索性空间数据分析方法,总结分析家庭能耗碳排放的空间特征与驱动因素,得出以下结论：(1)西宁市家庭人均能源消费量与人均能耗碳排放平均值分别为10.57 kgce/d和6.11 kg/d,取暖、厨房设备及热水器设备是家庭能耗及碳排放的主要来源;(2)西宁市人均家庭能源消费碳排放总体呈现出高值区(HH)、低值区(LL)相对集聚,而局部地区也存在高低值区(HL)和低高值区(LH)集聚现象,其空间规律呈现明显的异质性;(3)家庭收入、地理环境以及建筑特征等因素是人均家庭能源消费碳排放空间异质性形成的主要因素。  相似文献   

Migration,Sources of Income,and Community Change in the Nonmetropolitan Northwest     

《The Professional geographer》2013,65(4):418-430

During the late 1980s and the first half of the 1990s, the nonmetropolitan Northwest grew quite rapidly, narrowing the gap between the growth rates of the metropolitan Northwest, and oupacing national rates. This growth was largely the result of in-migration from regional and national metropolitan areas. Traditional economic base theory does not explain the recent growth, as employment levels in in the region's basic industries continue to stagnate and decline, and the sources of income for these in-migrants remain a mystery. This paper utilizes data from the 1990 Public Use Microdata Sample (PUMS) to determine the extent to which metropolitan-origin migrants are measurably different from oldtime nonmetropolitan residents on certain socioeconomic variables, in an attempt to understand the ways in which the newcomers survive financially. Analysis of variance (ANOVA) shows that newcomers are younger, earn less in wages and salary, receive more nonearnings income, and reside in more valuable housing compared with the resident population. Discriminant analysis shows that differences in the earned income measures are largely explained by age differences, while the nonearnings income and value of residence remainsignificantly higher for the metropolitan origin migrants even when age and earned income are controlled. While the analysis indicates that measurable socioeconomic differences do exist between the two populations, it appears that the current wave of growth and change in the nonmetropolitan Northwest is much more complicated than a simple newcomer-oldtimer dichotomy.  相似文献   

The role of metropolitan opportunity structures for understanding variation in the rate of Black household affluence     

Ron Malega 《Urban geography》2013,34(4):530-549

This study explores Black household affluence at the metropolitan scale and suggests that metropolitan-level opportunity structures shaped rates of Black affluence for the 100 largest American metropolitan areas in 2000. I hypothesize that affluent black households favored metropolitan areas of opportunity, those places characterized by having (1) economic opportunities, (2) favorable Black–White relational standing, (3) metropolitan diversity and residential opportunities, and (4) their location in the South, which serves as a Black homeplace. Results fail to suggest evidence regarding the role of the ‘new South’ for understanding metropolitan-level rates of Black affluence. More generally, findings from this study challenge our understanding of socioeconomic stratification by investigating diversity within America’s Black community.  相似文献